I loved the movie. I think it'll age as well as Beauty and the Beast, The Lion King etc - the quality of the writing, voice acting and animation are all superb.
The point of the "princess" thing is that Disney's poking fun at its own genre. The white "princess" was simply a spoiled Southern belle - good-hearted, but with a typical Disney princess "Some day my prince will come", happiness-is-tied-up-in-wedding-a-royal attitude, albeit exaggerated for comic effect. Tiana (who is a waitress, not Lottie's server - Tiana's mother was Lottie's seamstress, and stated to be the best in the city) is working to fulfil her dream of owning a restaurant, and utterly uninterested in marriage, let alone marriage to a prince. This is stated as blatantly as can be - the lead-in to the movie's " I Want" song, "Almost There", goes into it, as do numerous bits of dialogue and part of the song "When We're Human". It's sort of
the whole point of the movie - wishing on stars is lovely, but you have to work hard to achieve your dreams (while at the same time being open to magic and love). Unless your kids were dropped on their heads at birth, I think they'll pick up on it.

I'm not saying the movie scores 100% on the racial sensitivity stakes. For one thing, I'm a white chick who doesn't have the experience to make that claim.

For another, I've read on blogs about race that a lot of POC were upset by the miscegenation aspect (Naveen wasn't Black, he was vaguely brown vaguely European), wishing that a Black couple were shown and a Black man got to be the hero (although I'd argue that Tiana's father was a better role model than Naveen, but anyhoo). There were also concerns about the portrayal of Voodoo, and some disappointment that the first Black character spent much of her screentime, well, green. And some people objected to how
un-racist the movie world was - it was definitely a sanitised version of New Orleans, with only one statement that could be taken to be racist (or not) by one character. Then again, it's a Disney film, and not meant to be a gritty representation of the real world - just as Belle's life was rather nicer than the life of the average medievalish French peasant girl. On the blogs I read, the films sparked a lot of discussion and there wasn't a general consensus on whether it was "good" or "bad" as a whole.
But all that said, I think Disney rectified a lot of past mistakes with this movie. Tiana was resourceful, self-confident and hard-working; love found her, she wasn't pining for it;
she saved the day in the end, not the prince (think a reverse
Little Mermaid - Naveen made the deal with the devil in this one, and Tiana saved him); the Disney-parent-death actually had a point for once, and it was her father, not her mother (!) who kicked the bucket; and Mama Odie's "Dig a Little Deeper" song, with its theme of "what you want and what you need aren't the same thing", was positively paradigm-shifting philosophy for a Disney film.
Plus, the music was awesome and the film had honest-to-goodness
banter. Since when did Disney films have banter? I loved it.

So yes, I think your attitude is a little reactionary. Watch the film through. I don't think a film that featured a Black princess who started off at the top of the social ladder would necessarily have a more positive racial message, and it sure as heck wouldn't have had such a good story. (Plus, you'll see at the end of the film that being a princess doesn't relegate Tiana to a boring polished marble castle...) Belle from
Beauty and the Beast and Mulan from
Mulan also started out in fairly lowly/non-princessy positions, not to mention Cinderella. The point is where they ended up, and how.