what matters is the size of your save game. not gameplay time or how many companions you have.
i had zero issues till i got to 9k mb
now at 11k kb i'm hating life
i dare anyone to show me a 9k mb game character running around in solitude, in the middle of the day, and have no fps issues.
Just thought I'd pop back

I am now 10mb Save File - 40hours in and still no framerate problems, and Solitude is fine and I have done probably 10+ quests in solitude
The game occasionally pauses for a second when doing an autosave (which isn't very often)
I am not saying (and have never said) that you guys are not having problems, its obvious you are. But Not everyone is or will.
And I re-iterate to me this is obviously a problem with the hard drives, and how the game caches scenery and graphics on the harddrive.
And to prove I'm not "An Apologist" (and wow I hate that word and everyone idiot that uses it) I will say the problem that some of you are getting is the fault of Bethesda as I they didn't expect:
1) The battered state of some of the hard drives. (they obviously thought all ps3s could handle the amount of caching and disk access in skyrim - they were wrong)
2) The way some of you are playing the game. (I'm guesing the guys who first got the problem explored pretty much everywhere in the first couple of days, thats a lot of cached graphics!)
Please note the following:
1) Please everyone, give it a rest about the size of the save file - nothing to do with it. 5,6,7,8,9,10,11,12 Mb save files are nothing, they could be loaded so quickly the ps3 wouldn't even twitch.
2) The game caches graphics as you go along, if you've been pretty much everywhere round the map it would be storing a huge amount of data which slows the game down.
3) Please stop the "You'll get the problem soon enough" wow thats getting so irritating now. Some people will NEVER get the bad framerate because they have better hard drives or play the game differently.
It may be helpfull to the people that have got major problems, to detail the following for Bethesda so they can make future improvements in following patches.
1) Size of Hardrive in your PS3
2) How many times have you filled it up and had to uninstall games, demos, movies, music, etc
3) How long have you had your PS3
4) How did you play the game: did you just do a massive explore or just where quests take you.
5) Objects in the game, do you leave them lying around in the open or do you pickup everything and sell it all.
As I said I have not yet had any major problems and I think its because of the state of my harddrive and by the way I play the game.
I will probably never get the problem as I'll probably end up getting the patch before I get to the point where it starts to slowdown.
Finally to the people who say "why are you on the forums if your not having any problems".
I'm here to check for bugs in the game, and when I see the repeated posts which are obviously just wrong and are people jumping on the band-wagon. I feel I have to try and help out the mis-informed.
Some of you guys are acting like childish bullies and people checking these forums are staying away from a great game because you are having problems, they like myself are not.