index.js

// Fetch some User
var someUser = Alloy.createModel('User', {
  id: '1234'
});
someUser.fetch();

// Create new Profile controller
var someProfile = Alloy.createController('Profile', { user: someUser });

// Change model
someUser.set('name', 'New Name');

Profile.js

var args = arguments || {};

/**
 * Works, but you loose change listeners on the original model
 */
$.user.set(args.user.attributes);

/**
 * Does not work
 */
// $.user = args.user;

$.profile.open();

Profile.xml

<Alloy>
  <Model src="User" id="user" instance="true" />
	
	<Window>
		<Label id="name" text="{$.user.name}" />
	</Window>
</Alloy>