The developers at Splash Damage and Bethesda have confirmed that the first DLC for Brink will be free, as promised. Well, free for two weeks. Titled "Agents of Change," the add-on is set to release in early July. [Bethesda Blog]
I think everyone's frothing at the mouth over nothing.
I read it as in if we download the DLC within two weeks, it is free. If we haven't yet downloaded it and want to get it after the two weeks, then we pay.
So the purchase price for the first two weeks is free, after which it goes back to full purchase price... if you had it before the price change, it's still free.
Hopefully that makes sense.