Great deal on the power supply. If you can find a 600W for less though, it's all you would need even if you were to upgrade your video card. Ram looks nice with some low timings.
I would personally go with:
Phenom IIx4 955 BE $166http://www.newegg.com/Product/Product.aspx?Item=N82E16819103674
Asus motherboard, crossfire support $85http://www.newegg.com/Product/Product.aspx?Item=N82E16813131398
Arguably none none for gaming.
With your current video card, definitely none for gaming.
i5 definitely beats 955 in other tasks.
Another difference would be lack of support for Nvidia's SLI with the 955 board. You could choose another board that does support it, but then you wouldn't have support for ATI's crossfire.
The i5 is a better overclocker, apparently.
Ability to upgrade to a 6-core without having to dish out $1000 in Q2 this year.
Ability to upgrade to new bulldozer desktop processors? Then again, AMD might choose to go with a new socket when they come out in 2011 so it would be a gamble.