This lengthy thread at the Playstation forums suggests that some combination of the 3.10 firmware and Modern Warfare 2 is killing PS3 Blu-ray drives. Maybe it's true, or maybe they're all just drinking the kool-aid.
Forum members have reportedly pinpointed several reproducible freezes in Call of Duty: Modern Warfare 2 which they claim began only after installing the 3.10 firmware (the most recent release is 3.15). After experiencing this freezing, many members reported problems in other games, leading them to conclude that the firmware update adversely affected their Blu-ray drives.
Blu-ray diodes do have a finite life span, and it's hard to say if in these cases the drives have just run their course or if there is in fact something amiss with the new firmware. It's tricky. Sometimes, when an individual settles on an explanation for something, other people force themselves to find "evidence" corroborating that explanation. Sort of like how everyone started finding references to 2pac faking his own death in his music (those are real, though).
It could all just be a coincidence, or the Blu-ray diodes could be dying of old age, or there really could be some issue with the new firmware that is causing drives to crap out. If you have any insight, share it in the comments. [Playstation]