Why wasn't there a "Who Framed Roger Rabbit Sequel" Well how about a 3d Conversion?

This was a huge groundbreaking movie.  Released in 1988 the film went on to be one the top grossing films of the year.  The film was a laugh a minute and it seemed that it set itself up for a sequel but we never got it...


I am willing to bet that Disney is working on a 3D conversion of this film right now.  I just wish everyone involved with the "Roger Rabbit" would reunite for a follow up!