You sure can! We just bought ours last Sunday using the DC discount. Total came to $377.01 each. You're given a voucher which you can activate at the parks.
What we did: we bought our passes at the Disney Store at MCO. Picked up our bags, strolled to the store, no problem. They activated them right then and there. No fuss, no muss.
But you can buy them at almost any Disney Store and go the voucher route, too.