Don't know about the US, but my dealer in Toronto told me that I'll be able to place the official order in Jan '05 - I've already put a deposit. Pricing and specs will be at the dealership then. I'm guessing it's the same for you guys...

release is scheduled for end of February/ early March for A4 sedan/ Avant.
End of march for S4 (not been ordered yet).
Pricing not set yet; hopefully by year's end.