Tess is right - once the system is ready for the public and doesn't look like it's made for programmers (which will be soon), Evil Hat will send keys and information on how to redeem them out through BackerKit for the Kickstarter backers.
@ben00052 That would, indeed, be an error! The funny thing is, I played DFRPG for multiple years, and totally missed that! We've got a new rev going out the door Very Soon Now. I'll get this fixed up so that it goes into the one after that.
That's a great question! We haven't fully fleshed out our beta plans yet, but when we start looking for outside testers, backers will absolutely have priority. It makes perfect sense, when you think about it, because the backers know how the game is supposed to work!