Like Ihauoli said, Halloween and Christmas are basically given. And I don't think Valve would miss TF2's 10th birthday, so we'll likely see something for that. Personally, I'm guessing (and hoping) this update will contain the pyro update and jungle pack, as well as the final TF2 comic, although I won't be surprised if it's just a small filler update until the real updates that everyone is waiting for. The TFteam knows they've screwed up over the past few updates, so hopefully they'll be more thorough with ensuring the update works properly. I'd rather them skip TF2's birthday and make a good, working update than release a broken update.