In a Q&A with Playbill magazine, Mel Brooks says that he's currently working on a Spaceballs sequel. Here's the clip from the interview which starts off by talking about the big screen adaptation of The Producers.
Playbill: Will you have a role in it?
MB: It's doubtful, but I'm writing myself back into the Spaceballs sequel that I'm now writing, so you haven't seen the last of my face. Why another Spaceballs? It wouldn't feel right have anyone else play Yoghurt and the first one was the best experience I've had making a movie since Blazing Saddles.
Playbill: When can we expect that?
MB: Best case scenario: a week before the new Star Wars opens. Worst Case Scenario: a year after the new star wars opens.
Too many loose ends... too much crappy acting that covers up what could, otherwise, be an interesting trilogy. Unless ep III is something like 4 hours long, I just do not see them reconciling everything that needs to get done to lead up to ep IV while also making a fitting conclusion to the trilogy.
The prequels have don an admirable job of making me apathetic to the original trilogy- they are that bad.