Streep is my favorite actress (cliched, I know) and she'd be great (I doubt there's much truth to this rumor...yet) but I wanted an unexpected choice, she's a little too obvious. Glenn Close would have been perfect if they were going for an older actress, she can be scary, funny and emotional, though it might have been a "been there, done that" kind of role for her. Helen Mirren in a musical would be awesome too, especially as the Witch, given how sexy she is. With the younger actresses, Toni Collette is as good a choice as they'll find, but Marshall is such a star-F*CKer that he would probably only consider Collette (who has never quite become as big of a star as she should be, say the way Laura Linney became) for like the Stepmother just because she's not an Oscar winner, and her name isn't Kate Hudson.
Janney on the other hand would be perfection as Jack's Mother. Janney was in the recent reading, so if she is in fact in the movie it gives me hope for Anna Kendrick (who played Cinderella) to get cast.
"Some people can thrive and bloom living life in a living room, that's perfect for some people of one hundred and five. But I at least gotta try, when I think of all the sights that I gotta see, all the places I gotta play, all the things that I gotta be at"