If you bought Poker Night at the Inventory on Steam, you can earn the items just by playing the game and they'll automatically unlock in your copy of TF2. You can check that out immediately.
For Telltale Customers, you're in luck! If you got the game directly from us, you can still get the four exclusive TF2 unlocks. This page will figure out if you qualify, and provide you a key to plug into your Steam client
Woo! You're qualified! Here's your code:
To redeem: Click here to open up your Steam client and enter the above code for access to these exclusive TF2 items. Lucky you!