IT all depends on what you want.

If you are about PVp and combetive nature of the game, then you dont need a high end rig, because you will be  playing on low settings to increase FPS.

If you are about exploring then you might not feel so dazzled by the world around you(as there are some visuals that can only be seen with a high end card).

I have a laptop with GT555(3gigs of video memory) and i can play this game on medium. I was a bit disappointed but then again its an MMO, it's all about th social aspect and not the visuals so much.

But then again... it all depends what yuo want

P.S. GW2 is more resource hungry than skyrim, as far as i can tell from the expereience with my laptop