In a press release, developer 2K announced today that a new BioShock game is currently in development. However, the title (which has been in the works for 4 years at this point) won't be released for "several years."
https://www.notebookcheck.net/A-new-BioShock-game-is-in-development-but-it-will-be-several-years-before-release.447000.0.html