Today, PlayStationLifestyle (linked above) has revealed that SCEA has indeed registered PlayStationCloud.com, as follows:
SCEA San Diego Studio
10075 Barnes Canyon Rd
San Diego, CA 92121
SCEA San Diego recently mentioned while speaking to Gamasutra that they would be exclusively working on PSN game development. This goes against all speculation so far pegging PlayStation Cloud as a social networking service. Of course Sony San Diego could very well be developing a service or application, for the PSN with PlayStation Cloud.
Whatever PS Cloud is, it seems as though it's going to be coming from Sony's...