Just as we've recently discussed the possible future of GTA Online in light of the most recent DLC, Cunning Stunts, it seems that time for immediate speculation could be over.
Rockstar has kept up a steady stream of incoming content updates for GTA Online for quite some time now and has not shown any signs of stopping. So much so that each time a DLC is released, immediately the fans begin speculation on what the next update might bring.
Rockstar has tended not to reveal or announce DLC until very close to release in the case of major updates. For smaller updates, they've only announced the DLC upon release. This air of secrecy about the immediate future of GTA Online that the developers maintain is tantalizing for much of the GTA community, which is probably why they can't leave it alone.
It almost feels like a whole sub-community or culture has developed around GTA Online leaks. These leaks constitute real or fake reports of information about upcoming content being published before Rockstar officially reveals the update. These leaks, while generally condemned by Rockstar, are among the greatest generators of publicity the game has in its arsenal.

The history of GTA Online leaks has been a bumpy one. In the early days, before the release of the PC version, leaks were very rare indeed, and fake "evidence" was hyped up more often. When the game finally made its way from the couch to the desk, the leaks changed forever.
While consoles remain relatively closed systems that only people who are "in-the-know" can crack open, with accessing game-files being tough, things are different on PC. Very little technical knowledge is actually required to snoop around code and files that the devevloper didn't intend for player eyes.