Electronic Art’s product disclosures page reads as follows:
"PERSISTENT INTERNET CONNECTION AND ACCEPTANCE OF END USER LICENSE AGREEMENT REQUIRED TO PLAY."
One would think that the Games for Windows Live copy protection, which is similar to Steam's DRM, would be enough, but no. Electronic Arts thinks the "always on internet" DRM will actually stop piracy.
You'd think the Command & Conquer 4: Tiberium Twilight fiasco would have cured them of that delusion.
<UPDATE: The rumor has been by developer Adrian Chmielarz: F---ing Internets... No, Bulletstorm PC does not require any constant connection, only for install and for online play (duh!). Whew, that's a relief.>