I'm really going to miss all the original PN characters. I mean, I'd happily take Strong Bad or Tycho over Claptrap anyday. So, an idea I had for DLC was a DLC that brought back all the old characters. I know it probably won't happen (What, with the Homestar site being inactive for almost 3 years now.) but it would be pretty easy. They could reuse the PN1 models and add a couple of new lines of dialogue.
Ideas for names:
Original Night At The Inventory
Return To The Inventory
Classic Night At The Inventory
Also, since PN2 shows us the dealer, the dealer could be another character from one of the four series (Or another series.)
Leave your ideas and stuff here.