A few days ago, Bungie announced that they are giving players a ‘small, but legendary, token of gratitude’ to players in Destiny. Those gifts were deployed today.
You will be informed by e-mail when your free gift has been delivered – you can also check the Postmaster during the day to see if your gift has arrived.
You’ll be gaining a weapon in your package, which seems to be picked at random on delivery. It might be worth your while to pick up that controller and log in again to see what you’ve got waiting for you.