Happened just a few days ago. Was playing GT5 and noticed it was loading incredibly slowly between races, to the point that it got stuck and became unresponsive even though I could hear sounds in the background. Before that I had done the 2.10 update for the game, downloaded the new 2014 Corvette Stingray DLC and had done a few laps with it. It was exiting from that track when it started to slow. Tried quitting the game, which rebooted the PS3 and it froze while loading the XMB during the wave Tried getting into recovery mode to see if I could rebuild the file system, but I couldn't get that far. Got the yellow light and the power button became unresponsive.
I don't feel all that upset about it, despite the time I've put into GT5. I'll still play it, but not to the extent that I've had before since much of the game is a long-term affair. I've already scouted out a replacement and I've preordered this one: