I think most would advise waiting for Ivy bridge. I believe it is right around the corner. Are the 6870's in crossfire not performing well enough? I would think you could get another year out of those? Sounds to me it should be fine for your single monitor gaming. On the other hand if you are really itchin you might wanna do a complete overhaul
If you are going to keep your ram, psu, hdd and case you can easily afford pretty much new everything for $1500
Ivy Bridge CPU/Mobo = ~450-500
GTX 680

= 500
Shiny new 120gb SSD = ~160-200
... and that leaves you with a lil room to burn on extra goodies.