Before our trip in 08 we told our DDs that the character's couldn't talk because that's the way God made them, and they had to have someone do the voices for them when they were on TV.
They never questioned it, because we have always addressed the issue about how everyone is different. They have a cousin who is blind, so from a very young age they were taught about people's differences, and sometimes the differences mean that the person may look different, or they may not be able to walk, hear, see, talk, ect. Same goes for Mickey and his friends.
Both of our DD's are very bright, and on our first trip they were 6 and 8, and they still believed with all their heart that the characters were REAL!
We are going back this year and they will be 8 and 10, and we will also be taking my DS who is 3. My oldest DD knows about Santa, the Easter Bunny, and the Tooth Fairy, because she questioned it, so I told her the truth. Now her job is to help out, and keep the secret for her younger siblings. But with that said, she still believes she will see the REAL MICKEY when we go in July, and my youngest DD and DS, also believe.
They have no reason not to. They deal with the ups and downs of our life on a daily basis. They know the world can be a terrible place, and that there are bad people out there, and that we can't always have what we want, and that sometimes people get sick, and have to leave our family (just lost a wonderful aunt to cancer)

. But, they also know that a man named Walt Disney was magic, and he made a magic place where his cartoons could come to life and live, and we could go to this magical place, and escape the bad world once in a while.

Kids have to grow up fast as it is, why rush it. I would never tell them that the characters aren't real. There is no need to crush their dreams. I want to make my kids dreams come true. They believe, Disney World is REALLY MAGIC, and I wouldn't want them to see it any other way.
Yes, someday they will come to realize it's just people in costumes, but I hope that even after that they can still get caught up in the MAGIC when they get older. I was 31 before I ever got to go to WDW, and I was still like a little kid. I was in tears when I finally got to meet Stitch, and I have a photo of me hugging him (sure it was some poor little collage girl, in a hot outfit, with some weird woman crying and holding on to her for dear life

), but to me it was STITCH!!

Sometimes you have to overlook the obvious, and just BELIEVE with your heart and not your eyes.
