[Bob in St. Louis]

It isn't just speed that's a problem.  It's also monthly transfer limits. 

Yes indeed....and if there are a couple gamers in the house, and games become 4K, then I can see some major additional charges added to users that are above a certain threshold.

[jarcher]

I don't know - in major markets we don't seem to be that far off. E.g. here in the DC area comcast + verizon fios routinely offer 50mbps service in their bundles (they keep trying to get me to upgrade from 20mbps internet to a 50mbps + basic cable bundle for $10 more).  So 50mbps isn't so far off.  Seems like caps may be slowly raise as well : comcast is widely reported to be trying 300GB per month, but raising it according to the tier of service (e.g. 50mbps service having a 450GB per month cap).  Supposedly they'll even allow you to go over the cap 3 times per year before they charge you - at $10 more per month for every 50GB.

Nonetheless - I still think 4+ hrs for a download is too long even at 50mbps service.  And yeah, even if the movie is "just" 100GB, that means only 4 or so downloads per month before you surpass your current cap - or pay up more.  All the more reason why a median step of the "Ultra HD / 4K" blu ray makes sense.  At least until really quick connections with higher caps at more reasonable pricing becomes more universal.

http://arstechnica.com/business/2012/09/comcast-data-caps-hit-test-cities-range-from-300gb-to-600gb/

[North Star]

Seven or eight years ago, my location was able to upgrade from Dial-Up to DSL.   
So I was being generous saying I could stream 4k in ten years. 

Oh!