Oh yeah, sorry, I'm trying to read while working (got a bazillion things up on 2 screens), and a little tired today (got a bit of sinus).
If you already have the GF8600GT, then never EVER should you consider moving to the GF7950GT. Sure it's OK and will game in somethings better, and while I wouldn't upgrade the other way either, the GF7950GT is not worth the move IMO.
I could understand the other way around for DX10 stuff although I still wouldn't recommend it, and your jump from the GF8500 to the GF8600 was likely worth it, but IMO, your next jump should be nothing less than the GF8700/HD2900Pro.
Sure I'm dissapointed in the GF8600 and HD2600 as series cards, but really even a jump from the GF8600 to the X1950Pro IMO isn't worth the hassle, and I'd say it's a better option than the GF7950. Nothing less than an X1950Xt would make me tell you to return to the previous generation, and IMO, with those new cards so close, I'd say wait for them, they should offer you the power consumption of at least the X1950Pro and likely the GF7950, and yet offer you the power of the X1950XT or greater, and then add all the nice new features of the GF8600 series, and actually make those features playable.
I think at this point enjoy your rig, maybe overclock it as much as you feel comfortable with, but your next upgrade IMO should focus on those soon to arrive cards they have the most to offer (on paper sofar) IMO.