This movie is GREAT! The animation is beautiful, the characterizations are fun, and the story, while not totally free of formula or predictableness, is gripping and warm and funny and so on. The Phil Collins songs are forgettable, but oh well.
Plot, briefly: Sitka, Denahi and Kenai are Inuit brothers. There's a incident involving an attacking bear in which Sitka falls off a glacier and is killed. Kenai goes off to kill the bear, avenge Sitka's death, and probably also prove his manhood in the process. He finds and kills the bear... and then the spirit of Sitka turns him into a bear to teach him a lesson about love and hate. Meanwhile, Denahi, who missed the special effects show, mistakenly believes Kenai-the-bear is the-bear-who-killed-Kenai. So he swears revenge too, trying to kill a bear he doesn't realize is his own brother.
To turn back into a human, Kenai has to go to the Mountain Where The Lights Touch The Sky. He meets a talkative bear cub named Koda, who happens to know where it is. Koda agrees to lead him there, and on the way, Kenai is at first annoyed by Koda, but they soon become close friends. Finally they find the mountain: it's near where the rest of the bears go to catch salmon.
After the salmon run, the bears sit around telling stories. Kenai finds out that the bear he killed earlier was Koda's mom. Ouch. Then Denahi catches up with Kenai. More struggles ensue, in which Denahi and Kenai fall off lots of mountains. I don't think Disney's ever made a movie with so much mountain-falling-off-of before.
And THEN... at the end, something happens that I did not predict:
KENAI CHOOSES TO REMAIN A BEAR!
Disney has done transformation stories before... The Little Mermaid, Beauty and the Beast, The Emperor's New Groove... but I think this is the first where the main character doesn't go "Yaay, I'm human!" at the end. Wow!