Either

1) Bethesda knowingly and willfully released a flawed, broken, unplayable product. They didn't care that it would become unplayable after however many hours, because they already have your money!

or

2) Bethesda is so incompetent and amateur that they were unable to find an obvious, performance-destroying, and game-ruining bug! Invest a little in playtesting your products! This is shameful.

I'm inclined to believe that Bethesda just didn't care their product was broken and released it anyway. They got a ton of saps to shell out for it, now a bunch of them will go buy it for Xbox or PC as well! Double money for the extortionists at Bethesda! Congratulations. Brilliant marketing scheme guys.

Shame, shame, shame. This whole experience has left a sour taste in my mouth. I will never buy another Bethesda product again.

Just...gonna repost this here.. Since it's pretty relevant...

"There are a few threads on here with some answers just for this. Check out a few that I commented on if you want some real answers.
That said, this thread will probably get deleted among the mass of other threads as it isn't a Hardware or Software issue you are having- it's a complaint.

Just wanted you to know, I have Skyrim. The problem is affecting me. I agree with your frustration, but I can't agree on your points or logic.
Maybe in the patch, things will get better- maybe enough for you to enjoy the game. Cheers. "

I said it in an earlier, angry thread. Edited a bit- sums up a lot.
Man I'm tired...

If they didn't care they wouldn't be patching it. Follow the forums.

Bethesda: "The patch will improve long term play for PS3".

There are really only two things that causes this:

A) memory leak
overheating

"improve" not "fix" - It will still be flawed, as were the previous titles they didn't fix.