Tidbits channels Guy Noir in The Mystery of the Burnt Thighs. These MacBook Pros may have been overheating due to a bug in OS X SMB services. I had a similar heating problem with my iMac due to a buggy Canon print driver. A stuck print job pegged the CPU and just about cooked the iMac.
If my iBook holds up I'll wait for rev. B of the MacBook. I'm not interested in the MacBook Pro.
Update 9/3/09: Many years later Canon printer drivers are still driving OS X users mad and Canon scanner drivers are no better. Don't buy Canon hardware.