Well, shockingly, not a whole lot. As Cross told EW:
"I have not seen a script. I know the story they've got in mind, and it is great. I think it is [a] perfect continuance of the Bluths, although I cannot say anything. I know the outline is done. I am definitely looking forward to it whenever, if ever, it happens."
It's nice to see Cross continue to manage expectations there at the end of the quote. But really: There's a better chance of a unicorn walking into your office right now than Arrested Development ever getting made. As Gob would say, it's an illusion. (He'd also say something about his $2,600 pants.)
ยท 'Arrested Development' movie: David Cross says story is 'great,' but no script yet [EW]