Frankly xbox media centre better known as xbmc is the best media centre application I've ever seen and the most forward looking. Better still is its now moved from its xbox background to linux, mac and even windows platforms via the ability to compile the whole lot yourself under the GPL licence. So it almost comes as no suprise that some company has eyed up xbmc and decided to use it as the base for its own take on the media centre. Boxee is a funded team of about 10 people including a guy from Slingbox media.
Boxee is currently still in alpha and you have to be invited on the alpha to get it. I've looked over the blog and looking at the specifications for the linux version, you can certainly tell its xbmc underneath. I'm sure my replacement xbmc box will manage the alpha fine, so if you have a invite which you'd like to share with me that would be great.There's little about Boxee online but hopefully once I get an invite (wink wink nudge nudge), I'll be able to do some comparisons and post a load of screenshots (spoke to soon).
There's no douht xbmc is a powerful platform. Its great to see a open project branch out like this. Currently you have the main trunk which is somewhat controlled by the xbox media centre guys, then a osx only port by plex and now boxee. I look forward to seeing where others take it, but i'm sticking with the main trunk for now.