PS3 Skyrim is... yeah. I don't know if they ever fixed it, but depending on how many side quests etc. you did the game could start to get really sluggish towards the end. The workaround was basically to get the main quest done ASAP and clear up whatever else you wanted afterwards. I was lucky with it and never had huge problems with it but loading did get noticeably longer towards the end.
To be fair it's not entirely Bethesda's fault. Both the PS3 and 360 have 512MB RAM total but they handle it a little differently. The PS3 has 256MB system memory and 256MB of dedicated graphics memory. On the 360 though you have 512MB shared memory that can be split however the devs require. If say you're going to be using large textures you can cut the main memory down to 128MB and push the rest towards graphics. Or, if you're going to have a large open world that needs more system memory to keep track of stuff - like Skyrim or Fallout - you can bump that up and cut back on the graphics memory accordingly. The PS3 doesn't have that option and 256MB is really nowhere near enough for those games, so it runs out of system memory pretty quickly and starts thrashing the hard drive, which slows everything to a crawl. The games were designed for the PC and short of designing them from scratch with the PS3's limitations in mind there was never really going to be any way around it.