Yup, Kristen Bell not only went to NYU's Tisch, but she also has done stage musicals from REEFER MADNESS to Sondheim's A LITTLE NIGHT MUSIC. She also sang "Fame" at the Emmys and sang that "One Way or Another" song in VERONICA MARS. She is quite a talented singer, even if she is quite humble about it, and a wonderful stage actress (she was also on Broadway and talks extensively about the thrilling experience of getting notes by Arthur Miller himself).
Bell's talents are not in question, I believe she might be one of the most talented actresses of her generation, but I just think she comes off as too smart, clever, and cynical for Glinda. Only time I've seen her play a Glinda-esque role was in REEFER MADNESS and she played the role always giving a wink to the audience and turning on the camp. Glinda has to be played by someone who can convincingly be an ingenue, as in, if this were a golden age role, Barbara Cook would have been cast in the stage show.
Bell's persona is much more suited to Elphaba, she just might be too pretty for it.
"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"