If there's a limit, I don't expect you to reach it. I logged over 200 hours in a single character in Oblivion, and I save frequently and still never reached a limit. I believe I went into quadruple digits.
This is true, there should be no save limit as that would be extremely silly. As a rule of thumb i never have autosave's turned on, its a lot better and safer to do manual save's an additional tip is to make each of your save's a fresh one instead of overwriting a previous save, simply delete the oldest save after making a fresh one (i personally use 8-10 save slot's).
I believe someone has already gotten over a quad digit save as i saw in another thread similar to this last week that he was currently on 991 save's (insane i know haha) and nothing has been said since, if there was a save limit i guess it's safe to assume that it would of been reported by now.