I saw Harry Potter this week, and The Polar Express was featured in a film trailer. Looks interesting, but I'm not sure it will be a hit. It appears that the theme is belief in spite of nonbelievers, which is probably a more adult-oriented theme. I mean, do I want to take my (at that point) 5 and 7 year old to see a movie that revolves around those who don't believe? Some questions aren't ready to be asked yet... or answered by me
That said, it does look like it's going to be an interesting movie...