from what I can see it's basically like "on demand" where you can watch something anytime.
i wonder what it's true capabilities are though, because with HD shows on Sky you need to wait until most of it has downloaded before you can start watching, etc.
imo I would wait for proper real world reviews to see how good it is first.
also why wouldn't you just record shows that you wanted to watch anyway? so you could watch them anytime. or is that what the box does and it is limited to say 1 day's worth of programming, so you can't watch yesterdays but today's only?
personally i would save the cash and just set programmes i like to record or watch them through iplayer, etc.