First off, to placate the WO fanbois, WO is a very good game. My following comments will seem very nit-picky. But to me, the small stuff is very important, and mistakes are often more interesting than successes.
WO looks very good at first glance. The servers were stable and running. I didn't encounter any major bugs, only one graphical anomaly when a PvP scenario (battleground) popped right after a public quest finished. But that cleared itself up when I died.
I really wish Mythic had feature-locked, and just spent two weeks cleaning up the little things. There's lots of little things that are annoying just because they're so small and yet so obvious. For example, when you start the game, it doesn't give focus to the username or password field. So you launch the game, start typing your password, realize that the text field doesn't have focus, and have to manually click the field with the mouse.
Anyways, there's lots of little things like that. In the great scheme of things they're trivial, but it would have been really nice if Mythic had made the effort to fix them. Streamlining your entry into the game, so that you don't have to click through several movies. Not popping the EULA every single time. When you get a new title, clicking the Tome of Knowledge pop up should actually take you to the description of the title, rather to some other random page.
Now there's a lot of things that the game does well. The quest integration with the map is superb. I adore the way you can queue up for scenarios, continue questing, scenario pops, you go fight, and you return right back to your questing spot, and you can queue again. If there is one thing Blizzard should steal from WO, it's this queuing for scenarios. It even makes being on the popular side bearable.
In the end I rolled a Witch Elf on Thorgrim. I did try some other characters, but I didn't like the look, so I deleted them. I'll have to look at options more thoroughly later. The witch elf is pretty much a WoW rogue so far, but with far less clothing. One interesting thing was that you start with a combo-point generating ability at level 1, but you don't get a finisher until level 2. I'm not sure this was a good decision. In WoW, a level 1 rogue starts with a standard move, and a finisher, so the playstyle is obvious from the start. I also kind of see why Blizzard limits combo points per mob. It was very common for me to build to 5 points and then unload burst damage onto a new target.
I got up to about Rank (level) 5, and Renown (PvP level) 4. I do like how you get rewards from both questing and PvP as you level up.
PvP is interesting. In general, the Witch Elf is a decent character. I get a fair number of kills, killing blows and even solo kills. The only problem is that sometimes everyone clumps up into two ranged groups firing at each other. You can't really pick off anyone when this happens, as the group will nuke you as you approach.
I did get to try a Public Quest, and it's kind of cool. I even won the roll! I got some nice armor that revealed even more skin than my previous rags. However, I'm not really sure it's as revolutionary as everyone claims. WO doesn't seem to have "tagging mobs" as a mechanic, and that is a good change.
One thing about WO is that it does really expect you to be somewhat familar with MMOs. WoW had a much more gentle introduction into the genre, but the experienced player ends up modding the UI a fair bit. At points in WO, I was suffering from information overload, and I'm an experienced player.
Also, maybe I'm missing something, but wouldn't it be an obvious move to have the same keybinds as WoW whenever possible? Things like C for Character, etc. A lot of the keybinds are the same already, it just seems odd to me that they didn't copy the others. It would make it even easier to steal WoW players. It's like Microsoft Excel, when they were first entering the market, went to great lengths to ensure that the Lotus 1-2-3 "slash command" system was duplicated exactly in Excel. That made it a lot easier for Lotus 1-2-3 users to switch, as they could use all the commands they were accustomed to.
Graphically, the game is pretty good. The animations aren't quite as smooth as they should be, but it's pretty decent.
All in all, Warhammer Online looks like a solid, stable game. I still don't think I've found the class I want to level up to the cap though. I'll probably end up trying a few more classes on the weekend.
Finally, if someone could tell me where I learn professions, that would be great. I'm looting all sorts of stuff that are for professions, but I'm just vendoring it at the moment.