I have been looking at some XBMC forums and there are some really cool feature that are avalible.
I really like the program which puts trailers infront of your movies to give it more of a theater experence.
The other is a program which looks at your data base and checks which movies you don't have.
I'd like to see these both interated with couchpotato. Images getting to the end of a trailer, and having a button pop up asking "Do you want this?" This would be so cool.
Or looking through a list of the movies you don't have and clicking "Want" beside each.
I also found a forum about sombody trying to do something really similar to me: http://forum.xbmc.org/showthread.php?t=107931
There is also talk of creating a XBMC Backend http://forum.xbmc.org/showthread.php?t=105883
The Trakt addon also looks cool and it seems very popular. Keeping my eye on that one