To recap... video frame rates are:

Full HD 1920x1080 at 30 (29.97), 25 or 24 (23.976) fps
HD 1280x720 or SD 640x480 at 60 (59.94) or 50 fps.

Update: Operator's manual for Rebel T2i / EOS 550D attached here as a PDF (click link to download).