Those aren't 7 Megabits, those are 7 Megabytes in your calculation. But the whole 50 gb aren't used for the movie alone, so it's probably more interesting to look at only the movie data. There are already "copies" of movies with 1080p resolution encoded with h.264 out there, those are normally around 8-12gb. Which leads to ~1.5-2 Megabyte per second or 12-16 mbit/s (assuming 90 min of film).
Thanks for the information. I'm glad I didn't spend a dime on either of my HDMI cables. Question though. I have the 'generic' HDMI from my HD receiver to my LCD TV, and I have the Monster HDMI from my Blu-Ray to my TV. If there is no difference, this should not matter, right?