on the GTA Forums was messing around with the Rockstar Social Club and found an interesting item, a plane ticket. For Niko. To San Andreas.
While this of course means nothing concrete (it could simply be an homage) it could refer to the DLC, which mas been rumored to resemble entirely new cities. Unfortunately, unlike real-world airplane tickets, there is no departure date for us to pine over. So, San Andreas DLC? Maybe.