The Roku player has short video clips of MSNBC shows. It does not have entire shows to watch.
You will see tons of TV shows from the Discovery channel and National Geographic channels on the Roku player. However, these will be older TV shows. The latest media content from these channels will still be restricted to cable and satellite TV.
Basically speaking, the big media companies, the cable companies, and the satellite companies keep all the latest media content restricted on their systems due to their very lucrative advertising and subscription models.
The Roku player is designed to provide you with older media content. By older, I mean stuff that was broadcast 24 hours ago or stuff that was broadcast 60 plus years ago, and everything in between.