What are you expecting to happen with this code:
require(["dojo/domReady!"], function(init){});
That will not behave the same say way as:
dojo.addOnLoad(init);
If you want to execute a function named init after the DOM is ready, use:
require(["dojo/domReady!"], init);
Here's a working example that creates a map: http://jsfiddle.net/RyVE3/