Disney made the announced today, and Watson also announced the news on her Facebook page.
"I'm finally able to tell you… that I will be playing Belle in Disney's new live-action Beauty and the Beast! It was such a big part of my growing up, it almost feels surreal that I'll get to dance to ‘Be Our Guest' and sing ‘Something There.' My six year old self is on the ceiling - heart bursting. Time to start some singing lessons. I can't wait for you to see it."
There is no release date set as of yet.