Not that it's a huge surprise (although I always heard that Infinite was a bit of a disappointment in sales-versus-budget terms) but this long look at the Mafia III developer over on Kotaku is the first I've heard of a new Bioshock being in development.
This caused some tension, as some developers at Hangar 13 looked over and wondered, Why are we not there? The Parkside team was working with the familiar Unreal engine rather than volatile proprietary technology, and BioShock has a ton of cachet among developers and fans. Between Mafia III’s mediocre reviews and Rhapsody’s constant shifts, some members on the Hangar 13 team were desperately hoping to move next door. A few got to do it, but not everyone.
“The issue is that Parkside’s not ready for lots of people,” said one person involved. “They’re trying to be really smart about figuring out what the core thing is. They’re careful about not falling into the same problem every studio has, where they have too many people and nothing for them to do.”
Sounds like it's still probably a year or two away from being released.