NGOHQ has the first word on the shipping of the 7800GS cards from NVIDIA. These are the only G70-based cards available for AGP-sporting mobos, so you may be in luck if you're not quite ready to get rid of your current motherboard. They've also got a link to a review on their page.

"It seems that NVIDIA and their OEMs are shipping GeForce 7800 GS cards to distribution centers around the globe. Some of the distributors are waiting for the official launch, but others can’t contain themselves and have started distributing cards already."