It's available for pre-order today, ships on August 10th.
I noticed Engadget did a hands on and here's a quote from their article.
It essentially does all of the following:"Other additions include an OS X client, MPEG-4 support plus plans for downloadable apps like Boxee and an open SDK for developers."
HD placeshifter – Allows you to view 720p high definition streams of your home Cable TV connection and home video library over the internet.
DVR – Plug in your cable box or other TV source and you have the typical DVR functions of recording and playing TV.
Internet TV – Right not its YouTube for online video and CinemaNow for paid movies. In the works are many other web TV services including Boxee and Netflix.
Apps – The device should also allow you to play on Twitter and Facebook as well as do a lot of other stuff like play games and check the weather through third-party apps.
Live Broadcast - It can even broadcast video from your home live across the internet.
Home Network Media – Access and share video and media across your home network wired or wirelessly.
Before anybody gets too excited, this is the same company that brought us the HAVA, they're known for writing checks their ass can't cash.
I heard they also hired BP's Photoshop guy to design their GUI.
Here's probably the best place to read what they claim this thing will be capable of.