I just got this email from Joost (see screenshot below) asking me to take a Joost break. Problem is: I don't let my computer go full screen on anything. I multi-task. And when it comes to "lean back" viewing, I save that for my tv: my AppleTV (I just responded to a bunch of emails while catching up on Mad Men, which I bought from iTunes).
So Joost, get yourself on my AppleTV, and I'll watch you all day, all night, all the time. It would be perfect. When YoutTube came to my AppleTV it made the device worth having. When Joost comes to AppleTV, it will be worth watching Joost.