I really hope Nolan revisits his Howard Hughes script one day. Him and his brother both gush about how amazing it is, it just seems like it would be a real shame if it never got made just because of Scorsese and now Warren Beatty's films. I'm sure Nolan's take on Hughes would be very different from previous films about him, so here's hoping that it gets made at some point.
Plus, I'd be curious to see Nolan tackle a character based drama that has a budget lower than $100 million. He hasn't done one of those since The Prestige.
This is something that he'll likely do 10 years from now and it'll be hailed as the return to his Memento/The Prestige days. Likely be his Oscar win etc. It's the best thing he's ever written so I doubt he'll let it sit in a drawer forever.
I certainly hope Nolan revisits this project if not just to revive Carrey's career. Unfortunately, The Aviator seriously put a dent in the possibility of this movie ever getting made, but maybe Nolan will get Carrey in another movie.