Cloud computing seems to be the new "in" thing, nowadays. First OnLive appears at GDC, which forces David Perry to announce his own similar service -- which he was saving for E3 -- and now Sony has trademarked something called "PS Cloud." The trademark was registered "for use with a cloud computing data center management software, communications software, broadcasting services, and a long list of other terms," according to Siliconera.
There are many ways that Sony could be utilizing a cloud computing system, including offering a similar service to OnLive, allowing users to share downloadable games/demos or improving the PSP's remote play functionality. Whatever it is, we imagine it's probably quite a way off and, like many other trademarks or patents, could never even come to fruition at all.