And many many more.
Quick summary, courtesy of moi:
Two releases, The Athlon FX 51, and the Athlon 64 3200+. The main performing enhancing features of the two new chips are the on-die memory controllers (dual channel for the FX, single channel for the 3200+), and 1Mb of L2 cache. The FX is ruinously expensive, but overall appears to be the current best desktop processor in the world. The 3200+ is less expensive than the FX, but still too expensive for most. It is a good match for the P4 3.2 GHz, although the P4 still holds sway in it's traditional strong points, but the gap is much closer than before.
The P4 is pretty much destroyed in most gaming benchmarks. With Half Life 2 and Doom 3 just around the corner, this is likely to be a critical factor for many people building top end PCs for the latest games.
Both chips will be obsolete in around a year when the second generation socket 939 chips based around 90nm technology appear.
Intel's answer, the "Prescott" chip, will offer serious competition to the Athlon 64, but it has recently been delayed again to early December, amidst rumours of overheating problems.