When BeyondTV's latest version launched with BTV 4.9, one of the three, big new features highlighted by GeekTonic was the new capability to place-shift recorded shows over the internet. This place-shifting capability is now built-in to the web admin (gives BTV users access to electronic programing guide, settings and many other features across the web) page of BeyondTV. Something this feature also does is make it possible for Mac OS X users to watch recorded shows served up by a BeyondTV computer over the internet.
The Snapstream Blog has a nice writeup on how this works and what is involved. It's a pretty easy process that requires BeyondTV on the home PC and VLC on the place-shifting computer (PC or Mac). You can fast forward, rewind and "seek" to a certain spot of the video with your mouse. Looks like it works with both BeyondTV as well as the Snapstream Enterprise product as well.