I love what I've seen so far with Boxee, best interface of any media center, and I've been looking for a solution for a LONG time!
However, I do have a big problem... I often take a portion of my video collection on my laptop to play while on the road... sometimes I don't have internet access... OMG! I know, how tragic!!!
Anyway, AFAIK Boxee makes you login to use it...
So while I'm on the road I have to play my movies through the OS interface by double-clicking on files in the folders... I'd really love to be able to use Boxee while not on the internet... Like have a local account that doesn't use any of that internet streaming features and just allows me to use Boxee to sort through and play movies I have on my local hard drive.
So far, this is one of my only two complaints with using Boxee, which is amazing, because I have a very clear idea of perfection and have had tons of problems with the other media centers.