Sony-owned streaming company Gaikai has registered several domains for an unspecified property called PlayStation Cloud. The domains were uncovered by Kotaku sleuth Superannuation, who theorized that PlayStation Cloud will be revealed at Sony's meeting tomorrow.
The meeting is expected to reveal the first official details for PlayStation 4. Among the rumored features is backwards compatibility via Gaikai, which would be used to stream PlayStation 3 games to the console. PlayStation Cloud could very well be the name for that service, and possibly even more, given Gaikai's history of browser-based streaming.
We'll likely know more come 3 p.m. PST tomorrow--and you will, too, if you stay tuned to our landing page for the livestream!