No offense Scott, but I think you're a little off base here.  While everyone will I assume be pretty much wowwed when they go through the first time, that won't last forever.  Also, people who are not HP uber-fans are not going to be as enthralled as the people who post here.  And most important, there are going to be a lot of kids.  A whole lot of 8-9-10 year old kids.  This is fun.  The line will be fun.  They will be laughing giggling and pointing and discussing.  As they should be, and I know I will.  I don't think shushing would be the right thing to do.  If someone doesn't like, understand or enjoy being around rambunctious kids this probably isn't going to be all that enjoyable.  
I plan on taking my 7 year old nephew.  He has muscular dystrophy, but he can still walk now.  I guarantee he will be squealing in delight the whole time.  I bet I do too.