Having a patch chip is logical for MS. A .01ยข chip is better than rolling out a whole now line of CPU's.
However, i am curious. Perhaps one of the small flash chips near the CPU (as referenced here) 2048bits and 4096bits has some bigger signifigance.
Has anyone checked the other flash chip (pictured above, 2048bit) near the chip? Is it there on all 360's?
Also,
"According to IBM the CPU has 'an interface for a serial EEPROM in case patch logic configuration was needed during bring-up'." - Free60
Could one of these two chips link to Hypervisor code or even the 360 TSOP lock code? Doubt it. But curious.
EDIT: Better thought to second queston, potentially a boot sequence?