major nelsons blog will never give you exact details on whats in the update (as they want to catch as many as they can).
they may be locking out drive spoofing, and possibly banning consoles, but i cannot confirm this. i suggest everyone try to hold off until more reports show up.
just updated and now have error 74 and 1 flashing light
seems like the same thing they did with samsung drive downgrading which suggest its detecting a spoofed drive.
i took the leap and just updated my xbox. it didnt sign in straight away, but i am now signed in to live. dashboard and kernel version is now 6690.
just a bit of info:
Benq (not spoofed)
iXtreme 1.41 8x
original COD4 was in the drive during update
now im off to kill some people...