And he totally pulled it off, too. The mix of the Disney and MGM and Warner Bros. characters, all living together in a cartoon universe that bumps right up against old Hollywood, is something that had never happened before, and may never happen again. Obviously we don't know what Zemeckis will use if he makes a sequel to "Who Framed Roger Rabbit", which libraries he'll have access to.
It would be a huge feat if the sequel gets made, not the least of which is getting all the studios to agree to have their characters appearing again. I wonder if newer animation characters will come on board. Wouldn't it be funny if The Simpsons, those characters from Family Guy, and those kids from South Park were to come on board! It would be a riot!