We have the older Roku XD, which supports 1080p HD. It also supports subscription sports, MLB.TV for example, which streams all MLB games live for $100 a year. it does the NBA and NHL live streams. It does Vudu, Crackle (which is free movies), Disney, etc.
A lot the pay channels have Roku channels but most of the content is ancillary to the main channel, not the actual stuff. I think the next step will be for all the cable channels to start offering per-channel subscriptions on streaming, but until the contractual model changes with pay TV most of it will be locked up with cable and satellite. Their loss. It's not like people who ditch cable are going to go back just for The Walking Dead. But if AMC offered a $5 streaming option, maybe. Same with Discovery Channel, I'd consider adding that to our Roku for a few bucks a month. But I'm not gonna pay $50 a month to get 5 channels that I actual want.
It's like music, all the record labels screwed themselves with the Internet and streaming and now artists are finding avenues to bypass the bullplop and sell their records and downloads directly to fans. They end up getting more money from each sale since there is no A&R man, distribution overhead and the bloated label guys.
"Silent enim leges inter arma." -- Cicero