So there's a bit of speculation coming out of this years E3 convention already, and Take-Two Interactive is saying they're going to be there “in a big way”. Even though they didn't divulge too much information they have made it public that they have a couple of new games coming out including but not limited to Civilization Revolution 2 Plus, Battleborn, and Mafia 3 which are all set to release late this year.
Not to mention they're planning on dropping a new Borderlands game,
which has the fanboys sh*tting their pants, but the game is still in the development process and it will still be a while before a slated release date. However there have been rumors swirling around about what games could be coming out besides the titles that are already confirmed including a Bioshock Collection edition, but sources are now coming out and they seem to be heavily excited to jump the gun and announce that a Red Dead Redemption 2 will be coming out of Rockstar San Diego.
The rumors surrounding this claim have been mostly sporadic the past couple of years, and just last November a former employee of Rockstar had shared a teaser of information about the game through his Reddit account, not to mention Rockstar has just hired a bunch of new employees to work on an unknown project which has the rumor mill spinning out of control about a new Red Dead Redemption.
They want to make the series a permanent installment in the franchise, but just because there hasn't been any confirmed reports does not mean that they're not interested in continuing the business. Red Dead Redemption was released way back in 2010 and is one of the most critically acclaimed games that's every come out from Rockstar besides Grand Theft Auto. The game was so popular that they even developed a standalone expansion game called Red Dead Redemption Undead Nightmare which was released in October of the same year.
Aside from being critically received, this is actually a personal favorite of mine and hope to see some type of continuation of the story of John Marston, even though there would be no way to possibly resurrect him, so it's my best college guess that the story will be something of a prequel or he's coming back as a zombie, but it's all just speculation for now.