An improved and updated version coming later this year.
Remember how Roxio's CinemaNow service changed its name to RoxioNow just a few weeks back? That was, apparently, to clear the way for Best Buy, who now own the CinemaNow name. Aside from that, there doesn't seem to be a significant change.
It's all still powered by the RoxioNow technology, and the rental scheme doesn't seem to have switched around too much. You can rent or buy movies, many on the same day that they're available on disc. Only a few titles are available in high definition, and they're all documentaries.
Once CinemaNow gets up to snuff with the HD content, it could definitely be worth checking out. But $19.99 to buy a standard definition film just seems steep, especially when Blu-rays can be had for the same price.