Mine didn't come in the box (BBA 9800 non-pro), but it had a mail-in "rebate" coupon for the HL2 key. I received it a few months ago. Fry's and Microcenter did that deal, but now it's far too late to send it in even if you did buy it from one of those places. So yeah, you're out of luck.
my dad bought a 9800 non-pro and got one from microcenter. im using it now for the HL platinum pcak. ati voucher owners also get Counterstrike Source Beta for free too, it should be coming out in a few days.