The Cat in the Hat Comes Back

The Cat In The Hat Comes Back was the planned sequel to the 2003 film The Cat In The Hat with Mike Myers returning as the title character.

Plot
The cat returns to Conrad and Sally's place, rest of the plot is unknown.

Why It Was Cancelled

 * 1) The first film was a box-office disappointment.
 * 2) Fans of the book were offended about how many adult jokes were in the first film.
 * 3) Dr. Seuss' widow put a red light to all live-action adaptations of her late husband's work.

Result

 * 1) The film was permanently cancelled.
 * 2) There are plans for an animated adaptation of The Cat In The Hat and its possible sequel. Plans haven't been fully announced yet.
 * 3) Universal released two animated theatrical films, Horton Hears A Who and The Lorax.