Whiterun is fairly impossible to navigate. It takes me a good 2 minutes (literally) from the gate of the city to the general goods store. Dungeons are ok, until i get into a fight... And by ok i mean 15 fps, and by "get into fights" i mean 5 fps. In open fields, not only do i get <10 fps but textures pop in only when im right next to them and people show up behind me out of no where... Not only that but when textures do pop in, they look terribly low res, shadows are gimpy and lighting is jacked up but this graphical problem started when i updated to 1.2. My autosave is off, which pisses me off since I forget to save a lot and i have also reinstalled, cleared cache/game data/rebuilt database... No change. svcks...
I have ran into similar problems, and I've tried almost every trick and work around that people have been going on about on the forums. Even an SSD isn't doing anything.
Right now, I'm just holding off on my PS3 copy and just playing it on PC since it works way better. The only reason I got it for both systems is because one was a gift.
I really miss being able to hold the controller in my hands.

That said, there are some crazier bugs- curious if you ran into them. For me, it has completely negated magic resistance, dragons fly backwards now, and (as you know)
the framerate issue is worse. There are tons of other complaints and glitches coming up each day- so all I can suggest is wait for a patch or find a copy on another system.
You can check my posts, I advised someone curious of buying the game to seek out alternate copies as well.

Hope this helps. Cheers.
Also, sorry that you're having troubles with the game- I want my PS3 version working again. >.<