Is Falcon, the Xbox 360 with 65 nm parts, available yet? The consensus seems to be yes, but every source I can find merely links back to this post on the xbox forums.
Most of the evidence is circumstantial: the heatsink, PCB layout, and labeling of the CPU are different. There is one piece of non-circumstantial evidence, but I don’t know what to make of it. One poster claims overall system power consumption went from 110W to 65W, a 40% reduction. Even if the processor were responsible for 100% of the system’s power consumption, that would be extraordinary. Typically, a shrink to 65nm might reduce dynamic power by 40%, but that won’t result in a 40% in total power, since static power dominates now. A 40% reduction in total power from a process shrink hasn’t been typical since the transition from 250 nm to 180 nm, six years ago.