Do you want a new board so you can xfire? If that's the only reason I don't think it's worth it.
If you want a full upgrade to sandybridge, then I suppose you could get a GA-Z68X-UD3-B3
and a 2500k.
Tbh, if you can play all your games at the resolution you want right now, I don't see the need to upgrade. Unless of course you are sitting on a pile of cash and are really bored.