If you've been curious about Dragon Age 2 take heed about some warnings. I just finished the game and while it's quite impressive, there are some things I think marr the experience quite a bit. And no, I'm not talking about things like graphics.
Keep in mind that for some strange weird incomprehensible reason, almost everything marketed about the game plotwise is misleading. I think the only true thing from all the ads, trailers, hype, etc. is the fact that you become the champion. Very freaking irritating considering how much they showcase certain characters in all the Hype (A certain dragon lady comes to mind...). I think the story team was trying to be clever or something... "Aha! We got you there! I bet you thought you'd get to do this but instead you get this completely different thing instead!"
Second, this game suffers from a serious case of Inevitable Sequel. It even features a cliffhanger ending Halo 2-style with a huge amount of unanswered questions left over for the sequels. People looking for an epic adventure like Dragon Age Origins... this is not it. This is... hrm... this is more like a JRPG. Well... half a JRPG. At least most JRPGs have endings. This one doesn't even have an epilogue.
Thirdly, I really need to emphasize that this game is drastically different from Origins. Origins took me more than 100 hours to complete. It took me 20 hours to finish this. In other words, I completed DA2 in the same amount of time I finished Orzammar. When I got to the ending of DA2, I was asking myself out loud "Is this the end already? It can't be the end yet right?".
Lastly, if you run an Nvidia card, you may need to update your drivers before you play this game or you might encounter some pretty crazy stuttering issues.
It's still a good game but I think many people should know these few issues before they go in and get disappointed when they discover them first hand.