Check the time when you get there, because when we were there last June, I think the barber shop closed earlier (4:00??). I remember thinking that I was glad we'd stopped in at the time we did.
There were two people cutting hair (one was the gentleman featured in the Disney Magazine article last year), and about 3-4 people ahead of us.
My daughter (age 7) got her first haircut ever, and it was a lot of fun. They cut off about 12" (there was still plenty left), and we sent it to Locks of Love. Just to be sure I had some, and because I didn't want to keep track of it on vacation, I cut a little lock from underneath before we left for WDW to save.
My 10-year-old also had about 5" cut off. She did a great job with both their haircuts, French-braided their hair, piled on lots of Pixie dust, and gave them each tons of Mickey stickers. The youngest got the "My First Haircut" ears, too, although at age 7 they didn't quite fit! And the barber posed for funny pictures with a huge scissors prop.
The only drawback was it took us almost an hour and a half to finish from the time we walked in the door. I guess we had a lot of hair to cut.
She's going back in January for another cut, but I hope she doesn't start to think that we'll go everytime she needs one!