To make development easier, Rockstar has split itself into a few different development teams. For example, Rockstar North is currently developing Grand Theft Auto 5, but another team, Rockstar Toronto are one of the development teams behind the Max Payne series, and it looks like they will be the team behind an upcoming next gen game too.
It was previously revealed that Rockstar San Diego, the devs behind Red Dead Redemption, are also making an open world game for next generation consoles, but Rockstar Toronto has posted up a job listing hiring those that are capable of developing for a "Large Scale" title.
More digging around the job postings has revealed that the game is for both Xbox and Sony consoles, although a definite next-gen release hasn't been confirmed anywhere in the text. It's also apparent that the game is currently untitled, meaning that it's very unlikely that Rockstar Toronto are working on an open world Max Payne game.
Seeing as Max Payne is usually a rather linear game anyway, and that Toronto are fairly unheard of, it makes much more sense that this new development team could be working on a completely brand new open-world Rockstar game.
Seeing new IP from companies like Rockstar is always very exciting, and I cannot wait to learn more about what Rockstar has coming for the next generation.