We seem to have a robust CPU. I know with most PC CPU's a boost in frequecy of 600MHz means almost a doubling in CPU temp, BUT, usually there is a voltage boost also. I imagine it is because our CPU can be OC'ed like crazy without changing the voltage. I've yet to see a report of a CPU temp above 50C here at this site(though I may have missed it). So it would seem so far noone has shortened their CPUs life yet if TI has there spec sheets right. Makes sense since a lot of our PC CPUs are running hotter than 70C almost constantly and still last 2-3 years. Our CPU may be smaller, but the basic materials it is made of are the same.**EDIT: I see info out there that some of the Devs are possibly changing the voltage to the CPU(Although not sure this is even possible) in their ROMS..that greatens the possibility of overheating..but the temp allowances stay the same.**
Stability seems to be our main worry..and as I explained in another thread, each processor is slightly different in its clock capacity because of microscopic variations resulting from the manufacturing process. Remember our processors were spec'd at 600MHz, so TI could care less about how they run at anything above that.
Now the battery is a different thing also, since it does heat up fairly easily under the extra current draw from OC'ing.
The question does arise about the Current going through the CPU-which is what kills the battery faster at higher speeds. BUT again, too much current would result in a temp spike, which again doesn't seem to be happening in our case.