I'm a 4+ year veteran of WoW, have dabled in LotRO/WAR/others, and think that Champions Online is a refreshing take on MMO games. It seems to do a very good job of combining a lot of the high points (and wishlists) of other games, and minimizing the negative points.
Making the environment in a way that you can always play with any player (i.e. removing the "I'm on another realm" issue) is fantastic. At any time, you can view a list of all the other instances of where you are, and it lists which ones your friends are present in, so that you can switch to it easily. And you add your friend to your friends list once, and can see them regardless of which character they are on. I was quickly able to add my buddy, and see that he was in "Crisis in Canada #20", while I was in #10, and easily switch over to the same copy that he was in, so that we could play together. You can also log into the Champions Online website, and view your friends list, and their online status; what a FANTASTIC idea! I've been saying for years that WoW should do the same thing, with the ability to IM your in-game friends right from the site.
The character customization is spectacular. There are so may combinations, that I have yet to see 2 characters in-game that look even marginally alike. You choose from dozens, maybe hundreds, of costume pieces for each slot (e.g. hair, headwear, gloves, belt, weapon, skin markings, chest emblems), then you specify the general color theme of the costume and customize the individual coloring of any particular pieces that you want to differ from the theme. The possibilities are pretty much endless! And upgrades, unlike armor in WoW, don't change the look of your character, so you always look original. You still have a little upgrade panel, like the character panel in WoW, where you slot upgrade pieces in much the same way, though. It feels so great to look how you want, and not look like anyone else. (Also, long names, with spaces, are allowed. So "Captain Destructo from the Isle of Wastes" is a go, although "I'll PWN your face N00B" is too unfortunately.)
Choosing your powers is nearly as customizable as your character's look. You can pick powers from any of the different "schools", called "power sets". For instance, you could make a character that has a ranged ice magic attack, and then has a melee uppercut to punch you once you get close. Or archery and machine guns. Make a Chuck Norris character, complete with chest hair, that shoots you with a machine gun, then switches to a knife to finish the job. And once you start moving up in levels, and deeper into particular power sets, you can still pick up powers from other sets. The powers' requirements read like "In order to purchase this power, you must have 1 power from this power set, or 3 powers total from any other set(s)." So latter on, if you think that Chuck Norris should have a nice uppercut, in addition to his machine gun and knife moves, so be it.
I'm not sure why, but I had some minor graphics issues, that I expect to be worked out over time. The character creation pages would go black, like you turned the lights off, or flash on and off like a kid flicking the switch. It made it a little trying to create my character, but it worked out ok in the end. The game seems resource intensive, but probably not more than is to be expected. I run Vista x64 (and now Win7 x64), with 8GB RAM on a Phenom x4, with a ATI 4870 512MB. I have most of the features cranked up, at 1920x1610, and probably need to turn them down a little, since I get a few laggy FPS drops.
The combat is a lot of fun, and a fun change from WoW. It feels like you're playing Street Fighter or Diablo 3 (for those of you that played at BlizzCon), but with the 3rd person view of WoW. Killing enemies drop glowing powerup orbs, like Contra, that you just pick up instantly and keep on truckin'. It's a lot of fun to just jump in the middle of a bunch of mobs, and start fighting, and keep fighting until they are all dead. It took me a little bit to get used to watching the health bar, because unlike WoW and other MMO's, the mobs drop health bonuses, so after you kill one, your HP shoots back up while you're pummeling the next one. I suppose it does remove a bit of the predicability / certainty of what you can or can't kill successfully, but it makes combat more fast paced, and less numbers based strategy. When you're done fighting, your health recharges to full in just a few seconds, and you're ready to fight some more. I will caveat this by saying I'm only level 12 so far, so I haven't got into real "raid" boss battles yet.
Like WoW's recently added "dual specs", out of the box your character comes with two seperate "builds". Each build can be set as one of four choices, hybrid (soloer) / tank / DPS / healer (delineated by names I forget, like "Guardian", "Avenger", etc.), and all four are available to any character, although some are surely better suited to some. You can willingly switch between the two builds at any time, with a 2 minute cooldown.
Leveling is pretty questing-heavy. You don't seem to gain much XP from killing monsters, but get plenty from quests. The XP bar is actually two, which was a little confusing at first. There is a small bar, divided into segments like WoW, and a bigger bar that is solid. The solid bar fills up, and dump into one more segment on the small bar, then the big one fills up again.
All combat revolves around a resource called "energy", which is probably most comparable to rage in WoW. You have powers (abilities) that build energy, and those (usually heavy-hitters) that consume them. You have an "equalibrium point", which can be modified with gear upgrades, to which your enegry automagically charges up to, or bleeds down to, when you aren't fighting. It's not hard to build enough energy to use your better powers.
After completing the tutorial "zones", which will take a couple hours if you are taking your time to figure things out, you immediately get your travel power. Back when I started playing WoW, I think it took me like 10 DAYS (240 hours) of playtime before I was level 40, and got my mount. (Yes youngins', you used to have to be 40 to get the mount, and 40 took a long time before the dozen rounds of reductions to XP requirements for leveling.) You can move around quickly, and while some of the powers are very similar (e.g. flying, fire flying, ice flying, ...), they each have a slightly unique flavor, especially if you are trying to pick something that fits your character well. Chuck Norris is probably better suited to super speed running, than underground tunneling, for instance... or perhaps not.
The soundtrack of the game is pretty epic, and makes you feel like that point in an action movie where the music kicks in and something cool is about to happen. Unfortunately it doesn't seem that there are a great many different songs to the soundtrack, and it repeats quite a bit. I think in WoW it plays at random intervals, not continuously. Something is different, but it's hard to pinpoint what. The overall soundscape though is high quality, and feels immersive. When you're in the city, you hear sirens, chatter, and background clutter. When you're in the Canadian wilderness you hear animals, winds, and other sounds you expect.
The game controls are generally what you would expect, similar to other MMOs. There is one exception, however. Your character automatically faces it's target, which may be in another direction than the camera. You move the camera though, so if your guy is facing left, and you press strafe-left, your character will be walking forward, but the camera will be sliding left. This introduces (or actually removes) some of the tricky parts of combat in WoW, where you had to constantly keep mobs in front of you, especially while tanking.
The biggest concern I have for the game is balance. Your character's ability customization is so incredibly robust, it seems like an impossible task to even hope to be able to balance it. Imagine, in WoW, that you could build a new character from your choice of any powers/abilities from any combined classes. Do plate-wearing, warlock-esque fearing, paladin bubbling, dual-wielding, frost mages sound overpowered to you? That's exactly the kind of madness this game allows, for everyone equally. I can only imagine that very soon, geeks will be secretly using complex spreadsheets to tabulate all sorts of exploitative, and unintended ridiculously powerful combinations of power, that are nearly unstoppable. At the very least, it seems that even if this sort of exploitation isn't possible, that the margin of error has been widened, and that it's far easier to come up with a vastly underpowered or generally overpowered set of choices. Being as the game is so new, how does a new player know whether archery+fists, or machine gun+knife, is going to be a combo that is still playable at the end-game? The game provides a way to undo choices, one at a time in the exact reverse of how you chose them. So you undo choice #5, then #4, then #3, and so on, back to #1. But what if your mistake was in your initial choices? That's quite a bit of undoing. All in all, I guess we'll see how this plays out in the end, and this is just my speculation. I seriously hope it works out for the best, and that there are only different choices, not significantly good or bad ones.
Overall, Champions Online is a fantastic new MMO, with good graphics, fun gameplay, appealing customization, and an inherent ability to help make sure you are playing with your friends. Anyone who enjoys MMOs, like WoW, will probably find it a worthy entry in the MMO genre, and an enjoyable game.