I don't know why people are pinning such high hopes on the 8600 parts. Its been well-known for quite some time that they're going to be badly neutered compared to the 8800GTS and GTX parts.
G80 Roadmap
People knew the 8600 was going to be neutered but were banking on OC'ability with a die shrink, but given the 8600 specs you'd need to be able to hit something like 800-900MHz on the core to get similar performance to an 8800GTS running stock 500MHz. Couple that with the 256MB max on initial spec'd 8600 parts (I'm sure 512MB versions will pop up though) and there's simply no way an 8600 is going to be better than the newly released 320MB GTS from a price: performance perspective.
The most interesting part on that roadmap is the 8900GTS, especially if prices begin to fall shortly after release like the 8800GTS. Full 128 shaders with GDDR4 on a smaller process should be lovely.