What would be considered a "famous IP?" Red Dead , perhaps? It's not "new," though.
The Rockstar New England team is currently working on the "next version of a famous new IP," as evidenced by a current senior graphic engineer's LinkedIn profile. The project was spotted by Superannuation and then later cited by Kotaku .
According to the developer's profile page, Rockstar New England was one of several studios that helped Rockstar North with Grand Theft Auto V , which shipped to widespread critical acclaim last month. It's also worth noting that the Rockstar New England Careers page now sports no fewer than nine open positions , so it seems they're definitely cranking away on something. With GTAV out the door, perhaps the next logical "famous IP" installment would indeed be another Red Dead but there's no way to know for sure…
Ooh, I know, a Bully sequel! How's about that?