I'm working on such a program myself, actually. It's progressing, but the progress is slow. I'd welcome any suggestions as to what features to include in the package.
Here's a partial list of what I have in mind as of now:
1) Built on top of a real relational database. (I'm using PostgreSQL, but you could realistically set it up on any database that can be queried with SQL.)
2) Web interface
3) Stores all the information you would ever want about your images. (Camera, scanned thumbnails if desired, processing details, storage locations, etc)
4) Financial information. (A photography specific accounting system, essentially)
5) Submission tracking (to galleries or stock contacts) and sales information
6) Utilities like a function to generate the forms to register copyrights and generate web galleries.
I'm also going to be looking for beta testers down the road. Any interested parties?