She's signed on to do a Disney film called "Enchanted".
The article is really just a blurb which says:
Idina Menzel ("Rent") has been set to star with Amy AdamsAmy Adams in the Disney fable "Enchanted." Menzel plays the best friend of Adams' character, a princess banished from her animated world to live-action New York City.
Imdb doesn't update cast lists very quickly, so you'd have to check the messages. Your friend may be talking about Idina joining the cast of "Enchanted."