Great news in that the XBox 360 will be able to run games from the first release. A compatibility list has been published with a few titles from my collection missing (Splinter Cell, MotoGP, and RalliSport). Via Brad.
Update: C|Net Australia notes that Australia will be receiving the 360 on March 2nd, 2006 and that only the higher priced unit (which comes with the hard disk) will be backwards compatible. The Core version of the unit will need an optional hard disk in order to play the V1 games.