Thanks to The Leaky Cauldron for getting additional information from the British Board of Film Classification (BBFC) about the deleted scenes from the Harry Potter and the Prisoner of Azkaban DVD. The deleted scenes run a total of 4 minutes and 31 seconds and include scenes from the Knight Bus, Sir Cadogon, the Great Hall, Prof. McGonagall and one scene called Birdie.
A list of running times for each deleted scene:
00:00:28:05 | Knight Bus
00:00:37:10 | Birdie (no idea what this will be about)
00:01:01:07 | Great Hall
00:00:34:23 | Cadogon
00:01:49:10 | McGonagall & the password