While promoting his new film Darling Companion, Kevin Kline said a few words to the press about his role(s) in Frank or Francis, and why there's been a bit of a delay in filming. Via Collider:

Is the Charlie Kaufman film, Frank or Francis, your next project?

KLINE:  It could well be.  It depends.  It's a huge cast, and getting everyone in the same place, at the same time, and the certain amount of money in place to make the film, is tough.  I'm just waiting for a start date.  The producer is actually the same producer for this film, and he's very confident that it's all going to come together shortly.

So, what will you do while you're waiting?

KLINE:  I'm just going to go about my business of doing whatever.  I'm doing some Shakespeare this summer, briefly, and maybe another movie or something.  It depends.  I could get a call this afternoon saying we're going to start in two weeks, on Frank or Francis.

Could you talk about your role in that movie?  There's music in it, so will you be singing?

KLINE:  One of my characters sings.  I play three characters.  That sounds interesting, so I don't want to disappoint you by giving you anymore details. (Source)