This is a risk for Disney, returning to hand-drawn animation, to old-fashioned musical and to even older-fashioned fairy tale.
Or rather, it would be a risk if the studio didn't possess expert directors (John Musker and Ron Clements), a team of brilliant animators and a composer (Randy Newman) on top form. It doesn't matter if it's been done before, as long as it's done magnificently. This transports us to an olden-days New Orleans of tramcars, gumbo pots and racial segregation (sort of) where hard-working waitress Tiana dreams of opening a restaurant. But the dream goes on hold when a villainous voodoo doctor turns her and a visiting European prince into frogs; off the couple go to the bayou in search of a mystical crone, Mama Odie, who might turn them back into humans. Along the way there's wild fun to be had with a trumpet-playing alligator named Louis and a romantic Cajun firefly, Ray, while Newman's score mixes bluegrass, gospel and jazz to ebullient effect.
To be honest, I'd watch it all over again just to see Mama Odie's pet snake tip Tabasco into the gumbo. It's details like that which make this fly: Disney have turned the funeral march for old-school animation into a jolly hand-crafted pageant that shows vibrant signs of life even in the age of Avatar.