Dr.Dobbs recently posted a journal-style article by Michael Abrash, a programmer at Microsoft, discussing interesting technical details regarding the graphics capabilities of the Xbox console. The article discusses the Xbox GPU, full-screen antialiasing, the processor environment in general, the graphics pipeline, potential bottlenecks, and more. Abrash feels that even though the Xbox development environment is a familiar one, it won't be an easy task to fully optimize the consoles graphical performance in real-world situations. However, he does think that the Xbox will have a long run in the console industry and programmers will have plenty of time, working on a fixed format, to understand its architecture and performance quirks.
If you are interested in information on technical specifics of the Xbox graphics architecture Abrash's article makes an interesting read. For the entire article hit this link.