Uh yeah, so apparently he's already started shooting this. I didn't see a thread about it.
Starring Tony Leung and Zhang Ziyi.
http://www.imdb.com/title/tt1462900/
Some (ioncinema) are trying to predict we could see something, certainly not the whole film, at Cannes (do they do trailers at Cannes?). I would guess Cannes 2011 will be the earliest this thing sees the light of day.
EDIT: The "Production Thread" in the comments section has a dude named JeffreyC999 who seems rather connected. It's a good read nonetheless.