One, when you're dealing in millions (as in games/console combinations) then statistically some are going to conincidently have a failure - as Twest points out.
Two, due to nature of PS3 some may have other factors - for example you can put in new HDD with faster speed that will run hotter than default, and could tip scales.
So, while I don't doubt the reports, I'd need to see a statistically high percentage of failures linked to Uncharted 2 to feel it was anything other than just coincidence of one form or another.
Try to be reasonable... its easier than you think...