I would say yes, sort of. The standard Amazon Unbox client downloads all it's stuff in a DRM wrapped WMV file and puts it in a folder on your computer organized by show. So you can add a new video location to WMC and watch the videos that way. If you setup a season pass for a show and set it to automatically download to your computer, then you get the new episode automagically.
I say sort of because you don't get any information about the movie or show except it's title (which is really just the name of the file). In addition, you still have to manually delete show folders when they are empty. And to check a video back in, you have to use the Unbox client. So it's a bit kludgy at best, but it does work. I don't have anything but OTA channels, so I use it to watch a fair number of cable shows I can't get.