There's a new interview with Gavin Carter up at Beyond3D. Topics covered include shader model support, their HDR implementation, what they're optimizing for, and support for dedicated physics hardware (there isn't any), all of which should all be of interest to you if you're in the market for new hardware.
Also covered are some of the changes to the editor, just how fancy their shadows are going to be, Microsoft's sloppy developer kits, how different development is this time around (for the forty-six and a halfth time), just how much hacking they did to Havok, and whether a tree falling in a forest will make any noise if the PC isn't around to hear it (answer: it will, but the audio is downsampled to 8 bits).