Thanks for the advice re: cleaning. I bought a can of compressed air and sprayed my laptop (although I couldn't figure out how to get the cover off.. I tried removing about 1,000 freaking screws, but I must have missed some). Anyway, I am running a burn-in test now to see what's going to happen.
While this test is running, I've got a story to share with you all. I go to the Staples cashier to purchase the compressed air, and she asks me to see my identification. I show her, she says okay, and she explains to me that they will not sell compressed air to minors (under 18). Anyone have a clue as to why?
This burn-in test has been cranking for about 10 minutes now... the CPU temp is holding steady around 65-66 C (~150 F)... still a little hot for my liking, but I can live with it. Thanks a lot for all your help, and if this starts acting up again, I will be coming back.