Even if you've finished the Hustlin' Wit Dre challenge all three times, save any left over Beats, Certified Platinums, or Doctors Orders.
If previous "collection" challenges are any guide, after January 7, the unopened Dre items will turn into Mystery Bags. As in, dozens and dozens of Mystery Bags, if you've stored up enough extras.
So don't open them, don't throw them away. In fact, keep collecting more if you can.
If you accept these AFTER January 7,
you should be swimming in extra Mystery Bags.
Your Facebook Games Request page has duplicates of
everything in your Mafia Wars Envelope... so get both!
Remember, you have extra Dre items both in your Mafia Wars Free Gift Envelope and in your Facebook Game Requests page - so you can use the Double Your Free Gifts trick here, just like you (hopefully) did to complete the Dre challenge in the first place.