If you get an X2 I would buy a 3800+, fast enough for anything you can throw at it. And yes, putting to gpu's in SLI is a waste of money considering you get crap for performance upgrade and it will be outdated in no time flat, plus it can already handle it so why bother.
It is like me saying that I want to get my dad a computer with a 7800GT when all he plays is solitare, if that.
If what you have works, stick with it, only thing that may help would be an X2 for programming and other apps.
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