Old news, but it's first time I have heard of this so I figure I might as well post it to fill in those who haven't heard of it.
Earlier last year, in October actress Paula Patton reported on her site that she was going to play a character named "Witch Boom" in Roger Rabbit 2. Possibly a relative of or character similar to Judge Doom judging from the name.
This was before it was reported the sequel was getting stalled so I'm not sure if it's still happening.
Thanks to commenter Philip for letting us know.