For launch day, they offer about 1,300 movies and shows, with shows going for $1.99/episode and movies going for either "rental" prices of around $3.99 or "buy" prices at $7.97 and above (I see a recent film at $14.99).
They have a FAQ and it mentions that stuff you "buy" is always stored at Amazon and you can re-download whenever you want, but I don't see a definition of how long a "rental" window lasts (I see it is only 24 hours on the purchase pages). Additionally, there's a really bizarre "Pay-TV Blackout Window" where stuff you bought and viewed before can't be re-downloaded for a short time when it is playing on Pay Per View. That one is really weird, considering no sane person would re-buy the same movie they already purchased at Amazon months before.
I bought an episode of Studio 60 and the Borat movie to test it out. In about an hour, I should have both on my Now Playing list, and I'll check them out today and make a follow-up post about the video quality and experience. This looks pretty cool so far and I love that new movies on the day they are released to DVD will be available via Unbox. No more trips to the video store! (thanks Megazone).
The folks behind Snapstream posted a teaser about their new service Couchville. It looks like a pretty cool guide that also ties into the community of existing BeyondTV owners, by showing you what's currently popular (last item on the tour).
My favorite thing is the Google Maps style dragging interface. Click on the screenshot below to see a short movie of me using the draggable interface.