Besides Jack Bass, the list that Andrew Tyler shows Nate also includes the names Marc Pattavina, Amy Flint Catherwood, J.J. Geiger and Rachel Goodlett Katz - all of who were editors of Gossip Girl.
Blair refers to Lola as "Serena Light" when talking to Dan on the phone.
Kristen Bell (Gossip Girl) and William Baldwin (William van der Woodsen), although not appearing in any scenes here, also worked together on Forgetting Sarah Marhsall as Sarah Marshall & Detective Hunter Rush respectively.