The good news for "Y" fans is that a new script is being co-written by the creator of the comic Brian K. Vaughan. The bad news(if your not a Shia fan that is) is that "The Beef" says hes still definitely on board.
This is taken from a press appearance for Transformers 2...
"Y: The Last Man" is my favorite comic book. It's also [director] DJ Caruso's favorite comic book. We DO want to make it... Vaughn and [screenwriter Carl] Ellsworth and DJ are writing the script now. The script is not ready to be shot. DJ is making a different movie right now. He's making "Jack and the Beanstalk". There's just other things going on with DJ and I wouldn't want to make the movie with anybody else because he loves it like I do. But I don't think Vaughn is trying to give it to anybody else. I think that it is something that's very realistic, it's just not in the pipe for the next year."
I really don't mind Shia LeBeouf, he certainly doesn't annoy me as much as he seems to a lot of others. That being said, with my experience of "Y" limited to 2 or 3 issues, he doesn't seem right for the role of Yorick.