Should we only support link posts?

[lorensr]

Looks like it does a good job of filling in everything but category once you paste in a URL.

UX—the new post dialog could first only show the URL field and a disabled submit button. Then once it's filled, show the rest of the fields with an enabled submit button.

Currently waits for blur for embedly to activate—we could listen to paste event, and a throttled keydown event (so fires after X seconds of not typing)