Deadline is reporting that Tom Hanks will return as Professor Robert Langdon and Ron Howard will direct Inferno, the fourth Langdon novel from author Dan Brown. David Koepp (Angels & Demons) will adapt, and Sony has already set a release date of December 18th, 2015.
What is most interesting is that this seems to indicate that Sony/Imagine have decided to skip the third book, The Lost Symbol, which was supposed to be in development but little had been heard about it. According to the LA Times, pre-production was supposed to start this year, with a script from Danny Strong (Mockingjay) supposed to have been turned in by now. Ron Howard decided not to direct that one, with Mark Romanek stepping in.
The Lost Symbol could still be produced, but it seems like if it does it will be after Inferno.