I have just reviewed the status of Theater and will update the spreadsheet.
Using Server 3.0.5582.4 & MBT 3.0.5587.18453, none of the browsing commands work.
However, as James suggests above, I can do all the basic navigation commands (go home, go back, left right etc.), select, pause, unpause, stop playback, volume control, and also any direct play X commands.
This means that you can't browse to TV shows or seasons of a particular TV show or to albums etc.
However, you should be able to successfully ask to play a movie title, album, artist, or song directly by name if you know it.
To get to your TV shows you'll have to pretend you're using a remote control and navigate manually through the menus. It's doable, but obviously the whole unique advantage of voice control is the opportunity to avoid the awkwardness of standard remote control navigation. Unfortunately, at the moment that is still not an option.
UPDATE: 1 hour after I finished testing this, it seems a new MBT was released that has fixed the browsing problem. So be sure you're using at least MBT 3.0.5591.19855.