http://www.imdb.com/title/tt1568911/
Currently at 76% on Rotten Tomatoes.
Saw this last night. I thought it was pretty good, but not great.
[spoilers ahead]
The movie flowed nicely, using the horse to tie together the stories of the various people it encounters throughout the war.
My primary problem with it, though, was Albert, the boy who trains Joey. Due to a lack of character development (or perhaps just bad acting), I felt like his entire personality consisted solely of "I love my horse". As a result, I didn't care that much about him as a character, making the first act of the movie drag on, and the reunion at the end didn't have the punch it could have. I didn't feel that the horse was his more than anyone else's.
Besides that, though, it was a well done movie, and very cinematic. I don't see it being Best Picture material, though.
[/spoilers]