Gamespy just posted an article on the specs for the next Xbox. Note the last line in particular:

CPU – Xenon’s CPU has three 3.0 GHz PowerPC cores. Each core is capable of two instructions per cycle and has an L1 cache with 32 KB for data and 32 KB for instructions. The three cores share 1 MB of L2 cache. Alpha 2 developer kits currently have two cores instead of three.

I’ve been sitting on this until it became public knowledge, but when I saw a dev machine last year, it occurred to me that it’d explain why that Microsoft blogger was fired a year and a half ago.