www.boxee.tv

this was mentioned in the mac section here but is really US specific. However it is not platform specific. It can scan your network for movies and find description and trailer for it. It also links up with Netflix and Hulu.com and other content sources. I am running this right now on my Airbook but will install it on my Apple TV next week.

This is where it gets exiting because I can control it from my Beo4 Remote then. Netflix is still a bit bumpy even on my Airbook and I dont know how good Hulu will run on ATV since it pushes my airbook to the limit however that it finds the trailers and descriptions for my movies automatically and that it will let me stream movies to my ATV straight from my NAS is a killer feature for me.

It also has a "social" component. It lets me recommend movies to friends and they/I can see what I/they watched recently. 

It is in limited testing but I think can invite other people, haven't tried that yet, just PM me your email if you are interested. 

it looks very promising right now , US only though.

It installed fine on the ATV. It just added a new menu entry on the ATV.

10% of my movies were probably not recognized or recognized incorrectly. This was sometimes because of mistyped filenames or simple movie name duplication. However this can be corrected easily without keying in or renaming which is tricky on the ATV as there is no Keyboard. It gives you a list of candidates to choose from when you mark a movie as incorrect and sofar I even found funny German stuff I have on that list. It does have though a little on screen Keyboard that I can use from the remote, in my case Beo 4.

 The only grip I have is, the recognition of TV shows is not yet that sophisticated. I for example use the Show name as a folder and then have episode number and name in the file. Sometimes season is in the file or part of the folder structure as well. The index logic that automatically finds content description and artwork is not yet able to deal with this. 

However when I mapped the directory from my NAS Drive, I simply switched scanning off to prevent the mess of having TV shows added incorrectly. I can still browse and play them from the shared folder through the Add on.

 Oh and one more thing, Netflix streaming did show up on my Macbook installation, however it is not yet available for the ATV one it seems. Hulu seems to work, even though it stresses my macbook Air.

Some pictures, below. It has multiple view and sorting options to present the covers and the meta data it collected from the internet. 

EDITED: Pictures didn't upload unfortunately.