2K have announced via their forums
that the DRM restrictions on BioShock have been removed:
Good news! As promised, all activation restrictions, including install limits, have been removed from BioShock PC as of today. You don’t have to patch or install anything for this to go into effect for your copy of BioShock – it’s already done!
Enjoy your time in Rapture, and thank you for supporting BioShock and the 2K teams.
While it sure would be nice if it had shipped with no DRM, its at least encouraging to see the removal indicates that they've recognised that it's better for consumers long-term if there's no DRM.