The same thing happened to my son when he was 7. It was so dang cute. He kept showing everyone how to pull it and it wouldn't work for them. He is 11 now and never even stops to look at the sword anymore.
My DD did this on our last trip in 2009. It was hysterical. I was more surprised than she was!!! Others around her tried and could not do it including dh and dn. She did it over and over again after others around us tried it. She said she must truley be a queen to have that much power!! Yep, she is definitely my little drama queen. What happens next year when she tries again though???
I saw a boy pull it out during the year of dreams... Totally magical moment. CMs arrived to congratulate him with sash and certificate, the boy and his parents were beaming.
I hate to promote another site BUT the WDWRadio show did an interview with a "friend of Merlin" for the 8/29 (last week!) show and it goes into incredible detail as to how the show was done. It's very much worth listening to, but it may ruin some of the magic.
I saw a 4yo boy trying and trying so hard to pull it out and nothing happened. Honestly, I wish I knew where was the botton to push I would push it for him.
My kids (B/G twins) try this on every trip with no luck so far. They'll be turning 10 on our trip next summer and I'm sure they'll try again, but since they're so competitive with each other, it would probably be a nightmare if one could pull it out and the other couldn't. I'd love to see a little kid pull it up sometime.
We went to the first MNSSHP last week, and my seven year old was dressed as Wart from The Sword in the Stone. I was hoping he'd have luck and pull it out, but it didn't happen.