I have been moving all my media to a 3TB USB hard drive which is currently attached to a Mac Mini and using Plex on the Mac and Plex on the Roku and Android to play media. Some of that media is from DVDs and CDs, some of it is TV series which I let the plug handle downloading since it's effectively right on the router. Right now I'm just using sabnzbd but a friend of mine has his process completely automated with a GoFlex using Debian and sickbeard with sabnzbd to ensure all his episodes are updated each week automatically (he has his Plex running on a laptop, not sure if all the data has to come through the Plex).
Playing to Android and a TV with Roku would be fine, but the TV client is not as important, since I have a lot of options there from a Raspberry Pi to an Android HDMI plug.
Plex on the Pogoplug would be great, but I understand it's closed source. There appears to be some ARM versions, but haven't seen any which look promising enough to try. I could move the hard drive to the plug and not have to pull the movies to the Mac after download. Plus I can keep multiple drives in sync on the plug in relatively minimal space, for backup mobility. On the other hand, perhaps it's too underpowered and I should just have a traditional computer like the Mini or a Netbook.