Mine is doing the same thing. While plugged in and charging, the temp of the Memory Controller goes up to 59-61C and the fans kicked up to 3500rpm and as high as 6000rpm. Is this normal?
I also noticed that if I ran an application like iChat, the fans stayed constantly at the 6000rpm level.
i get this, and sometimes i get some webpages that take a while to load, as soon as i pull magsafe out, they load instantly. I think there is a bug somewhere or a memory leak, im gonna call apple support later and discuss