The DVR search feature is really nice but one thing I find myself doing is recording movies broadcast OTA. These are usually only on weekends or occasionally in the middle of the night. I have to search the guide a week in advance to see what movies are playing next weekend. I want to just be able to search for all movies in the search area. Similarly, searching for documentary would be awesome. Some advanced features would be searching for director name, actor name, etc. My wife said her TiVo allowed making passes based on things like actor or director name, and I would definitely use that too.
Further down the road it would be cool to incorporate movie data into the guide info like IMDb or rotten tomatoes ratings, art, etc.