Let's break these down, shall we?
Have you thought about it being a faulty disk? Someone on here who had the same problems, they returned their copy back to the shop, got given a new one and it now works fine on their PS3.
That same user posted the next day later reporting the same problems again.
Having the game on auto-save also cause some lag.
This actually does work! for about 5 hours.
Also, watch the amount of save files you have.People seem to have like 50 saves, this is also a contributing factor.
And yet there are some that report having over 20 saves that work fine. Until their saves start reaching 6-10 MB and the frame rate issues kick in. After that, even having one save still produces stutters in gameplay.
Someone mentioned overheating earlier on, also, the amount of time you spend playing the game may cause it. As someone who doesn't spend more then 5 hours a day playing the game due to work and Uni I may not have played long enough to experience problems.
There are users here that can't even play for 30 minutes, let alone 5 hours.
I understand that you're trying to be helpful, but none of those directly cause the problems with the game, nor are long term solutions. The game's engine just doesn't handle the PS3 well, it never has.
People have to realise that this forum is not representative of PS3 users, there's millions, and I am willing to bet that a huge majority have absolutely no problems.
Except that there probably aren't even a million
PS3 users that play Skyrim. There are millions of PS3 gamers, but not all of them bought Skyrim.