I've been lurking these forums for months, since before I bought my Blackbook. I knew before buying that the things ran hot. Mine typically maxes out at around 80deg. C when playing WoW or ripping a DVD (though I have seen it spike to the high 80s). There seems to be no real consensus as to how hot is too hot; that is, how hot does it have to get before you can say pretty firmly that the machine is not running as it should be. I've seen many people here say that anything running 80+ should be sent back or at least checked out, though I tend not to agree because many MB owners report temps this high. An Apple tech friend of mine says that you're just torturing yourself keeping a constant eye on the processor temps, because there is a failsafe that will shut the machine down before any real damage is done anyway. Notebooks run hut, he says, and there's no real use fretting over it. But really: how hot should a MB get before you take it in for service/call up Apple?