Not in most cases. In gaming it wont make a major difference.
I would personally save up for either a Sandy Bridge CPU or wait till the upcoming Bulldozer from AMD comes out. Would help lower prices on Phenom IIs if you really want to go that way.
Well i had the Athlon on my older rig and recently bought a sandy bridge i5 2500k and i can play every game now with no problems. Before playing COD Blackops i use to stutter now it plays butter smooth using the new i5 2500k with the same graphics card.
There is alot more difference between an Athlon and an i5 2500K than just the cache its like saying a ferrari is faster than an old ford because its red.
Thanks guys I think I may go with the I5 but the motherboards for 1156 socket are a little expensive, if I can build a decent I5 computer for $800 I will get it.