As part of their Cannes coverage, The Hollywood Reporter has confirmed earlier reports that Leatherface 3D is moving forward, with John Luessenhop currently in talks to direct. They have also found out additional details regarding production and franchise plans.
News from last year listed Leatherface 3D as a planned Twisted Pictures production, but the THR article states that Carl Mazzocone is producing independently. As far as the deal to produce "Texas Chainsaw" films, Mazzocone has paid for the rights to create up to six films, so they are definitely thinking of this as a possible long term franchise. Reportedly, production could start as early as this June and if that is the case, we'll start hearing specific story and casting details any week now.
As far as we know, this will have no relation to the remake and prequel produced by Platinum Dunes in 2003 and 2006. Previously released information discussed the intention to create a quasi-sequel to the original film, but taking place 30 years after.