Joost a moment
The problem is allowing people to download a piece of software for a PC they already own that has a broadband connection right next to it that enables them to try the Joost 'service' is easy. Getting a company to manufacture a device, with no proven market, that needs to be connected to your living room TV and to your broadband and have a customer pay for it... is very very different indeed!
Looks like a very tough old hill to climb to me... and then there is the problem of bandwidth and cost. The vast majority of people are on so called 'unlimited' broadband from their provider... the problem is they are in reality very much 'limited'! ...and lastly there is nothing worth watching on Joost... bit of a problem that!