@AC

would that be the same toshoba R100 that has a huge yellow ticker on its base stating under no circimstances allow it to contact bare skin as severe burns can occur? the dell latitude X1 and one of sonys vaio's of the same vintage suffres the same issue - they were all passively cooled and it quickly became apparent its not possible to adequatly passivley cool the cpu in a laptop!

as for the mac book air, looking at the internal layout id expect it to suffer overheating issues even with the new firmware - theres a lot of localised heat and very little ventilation, my biggest concern would be a 70 odd degree cpu that close to a li-ion battery pack that states do not expose to temperatures over 50 degrees...