Unexpectedly, I've just recieved my Joost beta invite and downloaded it onto my MacBook.
First run done and dusted and well, it's quite interesting as a concept, full screen, streaming video, presented in a TV like way on your computer (apparently will run on AppleTV as well)
It's a snazzy looking application, although a little choppy on my 512 Meg MacBook (oh god do I need to upgrade my RAM!)
It gives you a selection of channels that you can scroll through (haven't tried my Apple Remote with it yet, but I will in a mo) such as XL Recordings, Channel Frederator, Alliance Sci-Fi and The Soccer Channel... just like Sky then?... um.... well no, but that's what they're aiming for eventually and they'll probably get there if they get the right hardware support, eg: a set top box (a-la Apple TV, but I can't see Apple going for it somehow), bear in mind the guys who made this founded Kazaa and more importantly Skype.
I think it's main stumbling point is currently content (from what i've seen so far), but at the same time they've immediatly got a good cross-genre selection; sport, entertainment, music, shorts. As far as I understand it, it's advertising supported, just like normal telly (except BBC and movie channels etc), I've seen one advert so far for Vodafone, and it looked like a foreign ad at that, so not sure how well that's going for them, but you have to remember this is only second phase of their public Beta.
It's main attack apart from steaming video is the "TV 2.0"
I think content wise, they could do with hooking up with Revision3 and CurrentTV as well as some of the other podcast producers out there, as well as trying to get the traditional broadcasters to sign on.
So... although the current crop of content leaves much to be desired, saying that there IS Total