SO THE RELEASE DATES are flying around, moving backwards and forwards, but this is how we stand currently, as of this morning.
RV670 aka the Radeon HD 2950: November 19 (formerly 15).
RD790 aka the Radeon Express 790FX: November 20 (formerly 5)
RX780 aka the AMD 770: November 20 (formerly 5)
G92 aka the GeForce 8800 GT: October 29 (formerly November 12)
C72 aka the nForce 780i: November 12
C73 aka the nForce 790i: January (formerly December)
C72P aka the nForce 750i: November 12
Also watch out for AMD variants (MCP72 and MCP72P) of the 780 chipset on November 12. C73 is notable as it includes support for DDR3.
As it stands, the launches are mostly a week apart, with the 8800 GT coming in a little sooner. However, these are all subject to change, as embargos (and journalists) get pushed around at the whim of their PR masters. Look out for the glut of NDA-signers come launch day.
News source: THEINQUIRER