Q:
Have they talked about any other things about what's new in Longhorn?
A: Actually yes, quite a lot is divulged on the dedicated websites. News for the adverage Joe though is far more involving the superficial features.
Q:
And what about XNA?
A: XNA is Microsoft's solution to the every growing, 'MultiPlatform' problem.. currently in order to develop a Multimedia Title (aka Game) on the PC-CD, X-Box, GameCube, and Playstation2 you must create several versions of the engine.
Quite frankly all it does is waste time and money. Especially when it does take quite a bit of effort to convert an X-Box Engine to PC and visa versa. As such XNA has been designed to allow programmers to simply code everything up in a single language using a single API. Any end-system that uses Microsoft's XNA technology (Windows 2005 / Xenon / Revolution) will be able to run the exact same engine natively, or companies can choose to output to specific system.. at purely the cost of altering compiler settings and compile time. No engine reprogramming needs to be done.
It is still too early to tell if Sony are going to use this on thier redesigned Playstation Gen3 but really XNA is the next development platform for industry games.
Softimage|XSI 5.0, and Maya 7.0 currently in development both are going to be using this technology on the Microsoft Windows platforms, to provide artists with total pipeline integration.
In-fact Maya has recently been given an update for this exact purpose, which allows artists (suchas myself) to export full Shader materials that have been created and optimised within Maya using Microsoft's DirectX 9.0c (August/December) updates.
While other OS developers still bitch about the fact of Microsoft's dominance over that market, it is a market that they are quite obviously while not abandoning certainly currently back on the overall technology lead in that area. Simply because thier interests and the money is comming in far more from thier new 'MultiPlatforming' technologies.
Microsoft have been very slowly putting into place the technology, that not just makes them pretty much untouchable.