The first four reviews for Brave have come in, and they aren't very good. They aren't terrible per say, but they aren't exceptional either. The Metascore so far is 61. Slant magazine says at the end of their review that Brave is "nothing more than a caricature of a well-worn conceit (a princess doesn't fit into her shiny box, so she just breaks all the rules and does what she wants), neatly repackaged for another generation of young moviegoers who haven't met Princess Jasmine from Aladdin and don't realize that they're eating yesterday's leftovers". Even the more favorable review of the Hollywood Reporter says that this film really doesn't take any risks.
Of course, this could be wrong. The first four reviews of Alice in Wonderland suggested that it would be a great movie, but once the other reviews came in, it turned out to just be average. Hopefully, once the other reviews come in for Brave, they will have the opposite effect.