if you have lasted this long might want to wait for socket 2011
So at least 9 months, and possibly 12? For a system that if it's replacing 1366, will cost like $200 to $300 for a mobo, and like $300 or more for CPU's, is only useful if running Triple or Quad SLI, and at least 8 gigs of memory? I wouldn't hold my breath.
OP, I have pretty much the same system, just P35. Are you wanting to upgrade GPU as well, or install an SSD? I'm thinking that you would be fine if upgrading GPU, but probably not if using an SSD. You might see a 10FPS jump on certain games with the CPU upgrade, but it'd be hit and miss. Though I read in another thread that Fermi based cards are bottlenecked by 775's pretty bad.