Windsock, WoW and Old Republic should run satisfactorily on Sandy Bridge's integrated graphics. If you turn down some of the graphics details, you should get consistent 30-45 FPS.
For WoW, you won't miss much since the graphics engine is quite dated. I don't know about Old Republic, though, since I haven't played it. The graphics on that game look better, but I imagine the lower detail won't affect your experience that much.
All of this is from the viewpoint of a casual gamer. If you're hardcore, you should never settle for less than a good quality discrete graphics card. ;-)
Tenchu