Yea, I'm pretty sure I remember seeing something in there about them being at 24 FPS rather than 60 FPS, but I'll have to look through it again to confirm.I believe that is also correct. These 1080p movies will not take up more space than regular HDTV. For one, they are compressed with MPEG4 which provides much better compression than MPEG2. For another, they are most likely encoded at 24fps, like BD, instead of 60fps or 30fps like 720p and 1080i HDTV. Once the numbers are crunched, there is not a huge difference between the three formats.
EDIT: Yup, here's what is says: "Bell TV’s On Demand service has been designed to show 1080p resolution at 24 frames per second."