Stephen Amell revealed the following Legends of Tomorrow images via his Twitter and Facebook pages this evening, and as you can see, old man Oliver Queen is squaring off with a villain who looks an awful like Deathstroke (or Ravager?). For more details, here's the official plot synopsis for "Star City 2046":
THE TEAM ENCOUNTERS A VERY DIFFERENT OLIVER QUEEN – When a malfunction sends the Waverider crashing into 2046 Star City, our heroes face a startling version of their own future where they never stop Savage (guest star Casper Crump) and never return home. The city is in ruins and overrun by criminals, which thrills Rory (Dominic Purcell). Sara (Caity Lotz) is despondent over the destruction of her home and stunned when she learns what happened to her old friend, Oliver Queen (guest star Stephen Amell).
UPDATE: Here's Connor Hawke.