Although it has already been covered somewhat: Don't bother with Boxee Box. I own one, and it is adequate for Netflix, streaming local files, and a handful of "channels", but it is essentially an abandoned project. It doesn't even do Flash very well anymore because many of the sites have updated their Flash version, and the Boxee folk either can't or won't update the version on the box.
So the best part about the Boxee - the ability to have a nice front end to legally-available content from TV channels - is quickly disappearing. It now sits in the play room so my son can watch Postman Pat on Netflix. He'll say that it was worth the $180, but there are cheaper ways to get Netflix for the play room.