By now you've no doubt heard the twist this one puts on the old fairy tale; when Tiana kisses the frog, it doesn't turn him into a handsome prince, it turns her into another frog, and the two must set out together to restore their humanity.
Anika Noni Rose, as Tiana, is on the bland side even by Disney princess standards, but there are a few good voice performances here. Bruno Campos gives Prince Naveen more personality than Disney princes are usually allowed; Keith David oozes silky evil as the voodoo man, Dr. Facilier; and Jennifer Cody is quite funny as Tiana's best friend, Charlotte, whose obsession with finding a prince could almost be taken as Disney mocking its own princess obsession.
The old-fashioned hand-drawn 2-D animation is beautifully done, and comes across as charmingly retro in this era of 3-D and CGI. Particularly fine sequences include Dr. Facilier's final moments, a lilypad waltz for the two frogs, and a beautiful Deco-style fantasy sequence set in the restaurant Tiana hopes to one day own. Randy Newman's songs are competent, professional imitations of authentic New Orleans music -- all of the notes and rhythms feel right, but there's no soul to it.
Disney had reportedly been worried for years about doing an African-American princess for fear that they would somehow stumble into offensive stereotypes; I think they've avoided that (but I'm a white guy, so there may be something I've missed). For me, the character who crossed the line into offensive cliche was Ray, the Cajun firefly, who is a toothless, bumbling idiot.
This is certainly a vast improvement over Disney's most recent hand-drawn flicks, Home on the Range and Treasure Planet, and the crowd of 8- and 9-year-old girls in the theater certainly seemed to enjoy it. But the movie never soars in the magical way that the best Disney animation does, and if you're not a pre-teen girl with a princess fixation, you can certainly wait for DVD.