VirtualVTR from Gallery Software. We had Mark from The Gallery on our stand demoing this - it really is the business. For me to say such things about something that runs under OS-X is unusual! As a cheap (yet seemingly very powerful) picture-follow replacement for audio suites (as well as a play-in server for studios etc.) it looks hard to beat, and at £500 why wouldn't you? Contact the Root6 sales office!
Only one thing Mark - the "Unix powered" badge may have to go if the Open Group get their way! (see here).