I had a problem with several save games not loading properly anymore after I has suffered a "random crash". Loading a slightly older save game and moving to the same area also caused the loading screen to get stuck.
Turns out the crash caused "Skyrim.esm" to be corrupted; I ran the Local file verification in Steam and it said a file was corrupted, after it redownloaded the file the savegames loaded normally again.

So if anyone is having problems with infinite load screens, you may need to run a file verification.
Also I find it a bit worrying that a random crash can cause a critical game file to be corrupted.