"For best AMD performance right now, stick with Athlon X2 6400"3.5 starson by TheWake28
Pros: Works with any AM2 socket on motherboards; AMD "true" quad core design may be a diamond in the rough, but can AMD utilize it?
Cons: BIOS patch to fix problem cripples some aspects of performance; Not as fast as Q600.
Summary: The main problem with Phenom is that there's nothing to recommend it over the Intel quad cores (unless you're going for a SPIDER platform). There is as of now fairly significant proof to recommend an Intel quad core over Phenom, however: look at benchmarks.
The architecture is still behind Intel, and the fastest Phenom has a slower clock speed than the Q6600, Intel's slowest quad core. However, AMD is moving in the right direction.
Wait for a little bit. 3.0 Ghz and apparently much more OC-able Phenoms are coming.