Straight from the PBE Patch notes:

PROGRESSION UPDATES

• Favorites & Filters
  • Added the ability to favorite gun skins, Player cards, Sprays, Gun Buddies and level borders (favorites persist until un-favorited)
  • Added the ability to filter your collection (filters persist until next login)
    • Gun skins: Owned/Unowned, Favorites/Non-Favorites, Tiers (Select, Deluxe, Premium, Ultra, Exclusive)
    • All others: Owned/Unowned, Favorites/Non-Favorites
• Random Favorites
  • In addition to being able to sort through your weapon collection and set your favorite weapons, you can now equip the Random Favorite for every weapon type. This will make it so that each game you play, you get one of your favorite weapons (along with one of the variants that you own) at random each time you enter a match.

I've been waiting for this feature ever since Beta. Now I won't feel so guilty buying multiple skins for the same gun!