Lots of interesting content here, thought I'd share my experiences:
I wanted to watch the EPL football (soccer) on my TV, my source would be online steaming sites. I'm very sure they are legal
In addition, I wanted to access the BBC iplayer though a VPN and watch locally stored movies.
I've experimented with a jail broken AT2, and the embedded browser isn't great, either for the iPlayer, and streaming sports because generally they are still using flash.
Jail broken ATV as a movie player is OK, but it's clunky, and not wife friendly.
Streaming from an iPad is OK when VPN'd to a provider, but it's not brilliant for the fast action sports. Maybe better with the processing power of AT3? And again, no flash so limited.
Bough a Mac mini the other week, and it's awesome, really pleased just with the browser, plus flash reliability. Wife can use OSX, so it's a solution.
Currently using a logitech wireless keyboard, with a track pad as part of the keyboard.
I'm not thinking the next steps are to get plex into the mix for the movie playing and looking into the various plug ins and so on.
And get a smart(er) TV (or blueray) with plex client capabilities.