Play any of the participating Trading Cards Beta games to get trading cards. Up to half the card set is dropped through game play, the other half is earned through your collecting prowess.
Craft game badges
Once you've collected a set of cards you can craft them into a game badge. Like the current badges, they are tied to your account and are shown on your profile. Unlike the current badges, crafting games badges earns you tradable items like emoticons, profile backgrounds, and coupons. Level up your badge by collecting the set again and earning more items.
All badges now have XP which contributes to your Steam Level, a summary of your badge collection. You can view someone's Steam Level by hovering over their avatar. Leveling up earns you non-tradable items like profile showcases, extra friends list slots, and more.