My friend Vla pointed me to a couple of urls containing black & white info on Longhorn and Blackcomb, the respective succesors to Windows XP. While the "press" has been all ablaze about the inner workings of the next version of Windows (Longhorn is said to be v5.2 of the NT Kernel) nobody has been able to come up with any documentary facts on this from Microsoft itself. The web giant is keeping mum on this. We can however point you to this quote taken from the "REVISED PROPOSED FINAL JUDGMENT"
U. "Windows Operating System Product" means the software code (as opposed to source code) distributed commercially by Microsoft for use with Personal Computers as Windows 2000 Professional, Windows XP Home, Windows XP Professional, and successors to the foregoing, including the Personal Computer versions of the products currently code named "Longhorn" and "Blackcomb" and their successors, including upgrades, bug fixes, service packs, etc. The software code that comprises a Windows Operating System Product shall be determined by Microsoft in its sole discretion."
Source: (Point) U of (Part) VI. Definitions REVISED PROPOSED FINAL JUDGMENT
and this search reveals a further 5 leads all relating to the Anti-trust settlement.
So its official because its now on Microsoft, no longer a rumour or hearsay and you can say you saw it on Neowin :)