I have Skyrim for the PS3 and the PC. On the PC load time is no more than 3 seconds for anywhere Skyrim on ultra settings, no lag whatsoever and a much higher detail than on the PS3. Howver, my PS3 version has the crippling framerate drop and much longer load times after about 20+ hours and a 8 mb save file (more than double that on PC and no problems), I no idea what the issue is. Could be a cache problem?
This is a known issue for the PS3. Bethesda is working on a patch, and it's slated to be released after Thanksgiving.
Update: Looks like there'll be a patch in a few weeks for this issue.