Yeah, and all that comingling woth people from other companies is fun until we talk about IP, material and confidential information... basically as soon as a business actually deserves that name.
Pretty much everybody who looks for co-working places are working in non R&D type stuff.
People from other companies "comingling" is usually a REALLY good thing for the companies. Usually the best stuff comes out of this (Steve Jobs & Xerox's PARC)