it went really well (for the most part.) I ran for 3 kids ages 9-12 and one other adult. In short, a good time was had by all.

There was only one issue that I feel could be a good discussion. One player (my son specifically) was VERY enthusiastic. This is not a problem exactly, except that he wanted to do EVERYTHING. With no turn structure in DW, I had to struggle to give some of the other players spotlight time. One of the other players is much more quiet/shy and could quickly be overshadowed. My son became frustrated a few times because I had to make him wait so other players could give responses. To be fair, this is still better than having players who are bored/passive.

This lack of structure was the only real issue I had. Everyone had a good time overall. I did have to break them of "looking at a list of moves" instead of just describing what they would like to do. For example: At one point, my son wanted to try to incapacitate an attacker without killing them. He says "well, I can't do that, hack and slash kills them." I had to let him know to just describe what he was doing and how, and that he'd be given the opportunity. Breaking habits from other more "rigid" games! However, by the end of the session they were getting it. At the end, the Paladin had an epic one on one battle with an Orc Chief that was full of all kinds of moves that were not just Hack n Slash.

Anyone else ever struggle with making sure the shy types don't get pushed out by the less reserved?

Just reading through my copy of 13th age from Pelgrane Press. It's game world is of course stealable (just outlined enough but with plenty of "empty space" to fill in.)

But, the "Icons" story system would be very easy to import to DW, and would fit very well. Bascially, you have relationships with the major powers of the game world that the player gets to define. Then they can roll dice to see if those relationships will come into play into the next adventure/story. Cool stuff. 

Check it out if you like that sort of thing.