So my GF offered to buy me a new laptop if she could have my old one and if I played Aion with her. We've never played an MMO together and god knows I could use a new laptop so I took the deal.
The best way I could describe the game is that it's like a version of WoW where the game actually makes an effort to keep up appearances. The game is thoroughly beautiful, has a much better art direction and overall a better ambiance than WoW ever did. They further add to the experience by giving you cutscenes involving your character from time to time.
But the real kicker is that, after level 10, you can fly in certain areas and it opens up exploration and combat on another axis of travel.
I'm only level 12 so far, but I can say that if you've done WoW, you probably wouldn't get THAT much new out of it. I kinda wish I had played Aion and NEVER played WoW, since Aion is basically an improvement on all fronts.