Oh, Barbara Walsh would make a scary Momma Morton, but still, she'd be an acid fest as Velma, it'd be ideal to watch her do "I Know A Girl" and "My Own Best Friend."
I figured Jane Krakowski must've been offered the role a trillion times, she's hot-ish right now and unless she's a big fan of Chicago or Kadner & Ebb I'm sure she isn't interested in replacing Tara Conner and playing opposite Smokey Robinson. Same with Megan Mullally. Both would make great Roxies though. Krakowski would be one of the sexiest Roxies the show has had.
Vanessa Williams would be a brilliant Velma, I dislike her in Into the Woods and no one can touch Chita's Spider Woman but I think she's quite a good actress and like ljay said, she knows how to play the bitch role.
I don't see Chenoweth as Mary Sunshine, Baranski seemed like a great show, Chenoweth feels too cute for Sunshine. She probably would've surprised me, she's a good actress, but it's hard to picture.
"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"