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".
First Microsoft, now 2K ... public pressure does work. Music DRM is dead, now gaming DRM could be next (Sins of a Solar Empire was recently released without any copy protection, or even a CD/DVD check). Perhaps getting rid of DVD/Blu-ray DRM isn't that unrealistic ...