K10, Phenom X4 won’t bring much performance to your current games, even compared to the previous Athlon X2 generation. In best case scenario you will gain 20 to 30 percent, but only in selected games and we are talking about clock to clock competition.
This will be AMD’s biggest problem and you already know that the Core 2 duo versus Core 2 Quad almost score the same performance in current games at the same clocks. Even 20 percent is unreal today.
Both Intel and AMD are hoping that in next generation games both Core 2 Quad and Phenom X4 quad cores are going to be significantly faster than Athlon X2, but I would really take this claim with a grain of salt.