I have heard the same rumor, but have not been able to confirm that. I suspect that the revision 1.1 boards probably had higher rated MOSFET's added because of the fact that the Prescott's have higher wattages and thus were heating them up. That is an educated guess though, and nothing more. It makes sense though.
I do know that sinking those MOSFET's and PLL's is a very smart thing to do if you are OC'ing. I ran my board without them first to see what the difference was, and it amounted to 10C difference. Prescott's will put a hurting on them if they're not sinked. I'm gonna start sinking those MOSFET's and PLL's on every board I own from now on. They run soooo much cooler. I've seen too many pictures of blown out, burned up MOSFET's and I know those guys almost wanted to cry after all that work and benchmarking.
I recommend that to everybody I talk to wanting to build a Prescott based system. It's an easy mod, and if you use just super glue in the corners to hold them on, you can remove them and and still RMA your board while still keeping with the intent of the RMA process. It hurts nothing, and doesn't damage the board in any way that way. Use epoxy, and the warranty is definitely void.