component.find(...).getElement not working after Summer 16 release

Under Lightning Locker your components can no longer access DOM elements belonging to another namespace. So you can find a reference to the component but you cannot get the DOM element corresponding to it.

CharlesT is 100% correct - LS finally enforces what has always been a rule: "do not access the DOM created by components you do not own". This creates an implicit contract on code you do not control, from an author that has definitely not agreed to keep the private internals of their components static. This is basic encapsulation and a long standing software best practice in general. When you ignore this you are setting us all up for failure. Your code will break sometime and it's almost guaranteed this will happen when you least expect it. We live a multi author, push update world and the only way to insure trust is with string API contracts agreed to by both parties. You can also no longer .find().find() and reach into the component structure of another component. Trust is one of the key reasons we've developed Locker Service - not just for security.

What is your unsupportable approach actually trying to solve so we can help suggest a supported and maintainable alternate approach?