I can’t make any bones about my feelings for Tideland, and I don’t think anyone would argue with me that The Brothers Grimm is barely watchable, much less Terry Gilliam himself. But those two projects don’t change the fact that Gilliam is among the most interesting filmmakers alive, and I get a little thrill every time I read about a new project of his.

When that project involves Tom Waits cast in the lead, I need to run out and buy a new box of Depends.

For a couple of months we’ve been hearing little drips of new info about The Imaginarium of Dr. Parnassus, the script Gilliam recently completed with Charles McKeown, but today there’s some serious new poop.

According to a Spanish Q&A linked by Film Ick, Gilliam is moving along with The Imaginarium of Dr. Parnassus, with Waits evidently (hopefully?) cast as the titular doctor. Gilliam and Waits obviously have a certain rappor already; Waits made a short but memorable cameo in The Fisher King, and Gilliam used a tune off Bone Machine in Twelve Monkeys. For a guy like me who loves seeing Waits onscreen, every new Gilliam film has become a possible place for a Waits cameo…but dreaming of a leading role isn’t something I’d dared do.

Heath Ledger will join Waits, though his role isn’t known yet. Film Ick speculates on a couple possibilities, based on their previously published script review.

Details on financing are still sketchy, which means that in true Gilliam form, this could very well not happen at all. And since Waits dropped out of the last big role he was cast in (Prairie Home Companion) I’m not holding my breath until I actually hear that film is in the can. But for the time being, this is the best news all week.