I'd also caution you on Dark Souls. Not to drown out anything sensible by saying OH SO HARD DON'T PLAY SCRUB! It is a hard game, but not for the same reason other games are now a days. It's a trail and error dungeon crawler, but that is just the gameplay of the series.
The other issue to look at is that it has been confirmed that the PC port is having issues, and many of the issues of the console version, such as bad framerate and bad lag, are not being fixed in the PC port and in some cases could be worse as FROM has never made a PC game before. Also, it uses Games For Windows Live....so yeah.
While GW2 on the other hand looks fairly interesting, I have my game preordered and fully paid off, but that is more for the benefit of my friend who wants to play. I did play a bit of the beta and it is standard fantasy fare and the MMO gameplay doesn't really change, infact I find it a lot less intuaitive than WoW but it does have some interesting ideas. All classes have something that can heal themselves with so their "shouldn't" be a desginated healer class and they have dynamic events in the questing areas which are things that happen that other players have to assist in for the event to be successful and they are pretty fun too. I had one where a giant centipede burst from the ground and starting attacking all nearby players and it took all of us to kill it.