I dunno it looks and plays a lot like a crappier version of WoW to me. The game is not as responsive and the classes aren't as unique as WoW's but the art style is very similar (WoW looks a little bit better I think). The UI is probably about the same as the default WoW UI with a bit more freedom to move boxes where you like. The PvE levelling is similar to WoW's for the most part, just an endless stream of quests that drag you along from area to area. As a disclaimer I *do* like this game. It is fun. It's just not the greatest thing to hit the shelves since the dawn of the MMO. Anyway... More bitching and complaining.
Most of the content is soloable with mobs having varying ranks to display their difficulty (i.e. Champion, Hero, Lord, etc mobs are harder). I would say about half the classes can solo Champ mobs close to their level while hero or lord mobs should be impossible to solo. Most of the mobs have the typical tank and spank dynamic starting out which I think yields to a bit more scripted content higher end.
The biggest difference between Warhammer and WoW imo is the fact that the game keeps a sort of global score for PvP in certain areas. Like how WoW keeps score for the towers in E Plaguelands if it did it for a larger area. Warhammer does this for the "contested areas". It then assigns buffs to the winning side and resets.
I don't think the combat in Warhammer is as good as the combat in WoW. This was also my biggest problem with DAoC. The combat system was so terrible it made it hard to enjoy the rest of the game. Warhammer has the most annoying universal cooldown system of any game I have ever played. Combat does not seem to flow properly. This is especially bad on classes like the Swordmaster and Black Orc who's combat gimmick seems like it is designed to have them "dance" through their special attacks. You cannot really judge when to hit your next attack by your character's actions, you have to watch the hotbar until you get used to the timing and ignore what your character is doing. It also seems to have some nifty effects where if you time it too perfectly your character will do the animation for a special ability, the ability will think it went off starting it's individual cooldown in addition to the global cooldown, but the ability will not have fired. There are a ton of other annoyances here but suffice to say if you are expecting the combat to be as refined as WoWs you are in for a disappointment IMO.
PvP is what this game is supposed to do well. I think it's quite fun personally, especially the fact that you can get really good exp from killing other players. The biggest problem is that like DAoC this is a carebear game at heart. Like WoW the world is laid out into consentual and non-consentual PvP areas. Unlike WoW the consentual areas are there throughout the whole game. So you can basically catass your way to max level without any fear of having someone switch on your nerd rage. On top of this if you as a higher level person are thinking of molesting lower level characters you can forget it, you will be turned into a chicken! So yes like DAoC this is NOT a hardcore PvP game. It is a consentual PvP game. That being said they are looking at putting in some sort of open ruleset that will bring the game up to being somewhere between only slightly more pussified than WoW or roughly equal to WoW PvP wise (i.e. you have non-consentual PvP everywhere but killing newbies still = chicken or maybe they will take the chicken out).
Really the only thing this game brings to the market are public quests and open groups. Everything else has been done before and done better. The whole time I played this I just felt like I was playing the bastard child of DAoC and WoW pussified further for mass consumption. *shrug*
But!! It is entertaining... And it has the same two lovely things that AoC brought to the table. It's NEW!!! And it runs well enough that you won't crash every 5 minutes!! Sadly this is all it takes to get me to play a non-korean MMO.
Oh last bitch, you can't talk to the opposing team. I HATE this in every single game that implements it. (WoW and DAoC I am looking at you!)