I haven't seen any case law, but just looking at the text it certainly looks like VPS hosting can't be 512(a) in normal cases without an incredibly distorted reading -- the VPS hosts systems don't do "intermediate or transitory storage" of client data, they do relatively permanent hosting at the direction of the client, exactly the kind of relationship addressed in 512(c).

512(a) would apply to, say, an ISP that stood between a system hosting allegedly infringing content and those accessing it, not to the owner of the physical system hosting that content who allowed a third party to control a VM on the physical system on which the content was hosted.

http://www.law.cornell.edu/uscode/text/17/512

No case law, just Chilling Effects: https://www.chillingeffects.org/dmca512/faq.cgi#QID127