Interesting question. I actually hate dude in drag movies. Mrs. Doubtfire was a long way from White Chicks so it came off better.
Trying to get Ryan in a "younger woman's outfit" will go down in large flames so I wold hope they choose a chubby chick in sweats.
Of course there will need to be some latex involved. Something similar to the movie where he played fat.

It's a good observation Scott. One thing I might add about Mrs. Doubtfire is that the story worked b/c Robin Williams really DIDN'T convince everyone. Remember, his son and oldest daughter discover the truth in the second act. That he goes from having to convince them, to having them help him convince others really benefited the believability of the story.

Did anyone else hate having to accept that Mrs. D wasn't real, no matter how many times they watched it? There was something very devastating about it for me....like the Jimmy Stewart character in Vertigo realizing that the woman he loves isn't dead, but in fact, never existed....much more tragic.

I hope that Loeb really though about this as he created the drag persona, and didn't just use it as crutch for gags.