You guys know that the movie portions of the blue ray disc(english and subtitles) are around 10-15 gigs right? All the extras are what adds up to this massive 50GB file size( I say 50, when in reality it's around 25-30 gigs).
15000MB/12.5MB=1200s/60=20 minutes.
When was the last time you ripped a bluray disk? The feature portion of the disk can easily reach 25-30GB without the extras.
@Others who've posted in this thread - I think some of you have proven my earlier statement about not being able to tell the difference between a youtube 1080p stream and a good HD source.
Make friends with iNetVideo.com if you want some cheap bluray vids - and keep an eye out at the constant stream of specials from BB and other brick & mortars.
I agree that optical disk is on its last legs - and it's probable that bluray will be the end of it... but I don't think there's currently a viable alternative for audio and videophiles.