Doh...jo!
I was doing a dojo.require("esri.<no such namespace>");
Dojo has a timeout for loading cross domain resources. When you try to load something that doesn't exist, it times out. However, it doesn't tell you which resource it crapped on.
Had to comment out individual requires to find the culprit. For some reason, I thought esri.InfoTemplate was a namespace/library, when it's really just a class.
Brad