Well I just got back from seeing this movie, and I must say I was pleasantly surprised. This movie is easily one of if not the best Christmas Carol ever, which is no surprise because Disney is behind it.
There really is no comedy in the movie, despite Jim Carrey's role. This movie is probably the closest to the book out of all of them, which is good because the story is very dark. Jim Carrey is excellent as Scrooge as he portrayed the old humbug very well. The other voice overs were well picked also.
This movie is not required to be seen in 3D, but you can tell which parts were made for 3D. The animation is excellent and it is a welcome treat to hear traditional Christmas carols throughout the movie. The pacing is superb, it's not too fast and not too slow.
The one factor that really brought the magic out of this movie were the ghosts. All of the ghosts were portrayed very well, and minus Christmas Past, all of the ghosts were creepy! Jacob Marley gives a new sense of dread and despair, Christmas Present shows a truly dark side underneath his jolly laughter, and Christmas Future is by far one of the scariest ghosts I have ever seen in a movie. The last half hour of the movie which includes the end of Christmas Present, a.k.a. the two decrepit children, and all of Christmas Future, are some of the darkest scenes in Disney movie history. In short, these are the best ghosts out of all the Christmas Carol incarnations.
Overall, this movie is outstanding. It displays the truly grim and depressing tone of Scrooge's life very well while still keeping a light hearted feel in the end. I highly recommend seeing this movie.