I would say that you should sit tight and wait a little more longer. Your cpu is good and you will not be seeing much of an improvement if you do make the jump.
IMO wait a little more longer and then make the jump next year.
I bought a 4400x2 to rplace my 3700+ i havent installed it yet, all i can say is i'm gambling that the future games and applications will soon take advantage of the dual cores.
I will never look back at my 3700 SD, even when I had it at 2.75. My X2 3800+ has been simply great. Plows through my video encoding in a little over half the time that the 3700 did, keeps at least one of my DC clients going while doing stuff like resizing pictures, ripping videos from my DV camcorder, etc.
Looking at your sig, going to a dual core chip may bottleneck your 7950GX2 slightly in games. However, a lot of CPUs will be the limiting factor with a GX2 One of the 4200 or 4400 X2s should get to 2.4-2.5 without too much trouble, and at that point I'd consider moving to an X2 very much worth it.
Stick with the Single Core for now if you only game. Over the last 18 months I have had more than my fare share of problems gaming on dual Cores. Granted many were an easy fix, it was still a pain in the arse. Now for everything else, they kick rear, so dont hesitate if you do more than just game.
At 2.8 and if you mostly game then don't bother unless u have money to burn and can deal with a possible lower overclock. If you do a good bit of video encoding, etc. then it may be worth it!
Everyone weighs the effects of a dual core on their system's ability to game... But I think having a dual core is more than that.
I mean, windows really does PLOW through anything I throw at it... Sure, word and the internet really dont tax your system too much, but everything, no matter how memory/cpu intensive I use runs smooth as butter.
If you game, and only game... Only things employing the Havok engine will really show improvement... If you do other things too, dual cores breathe usable life back into your system.
depends what you do with your PC... I encode divix from mpeg and that takes along time... so with X2 i can encode and play BF2 or i can only encode video at almost 2x as fast
if all you do i game then you are a nerd... and your 3700+ is fine but id get a DC and you honestly will love being able to have 2 CPU intensive programs running at the same time...