Yup. You asked for it (last year), and now, it's gone! 2K's Elizabeth Tobey has announced on the game's official boards that, as of right now, "all activation restrictions, including install limits, have been removed from BioShock PC". And not only gone, but gone automatically on 2K's end, meaning you won't need to install anything, uninstall anything or even check a box. SecuROM fanboy, you have our sympathies
Activation limits removed on BioShock for the PC [2K]