No official confirmation of the subject of this conference, but a likely highlight seems to be a big reveal of the next PlayStation Portable, likely not the phone one. The conference is supposed to start at 10 PM for the West Coast (U.S.) and 1 AM for the East Coast (U.S.), so that means some of us will be staying up later than others. The time won't be horrible where I live, so I plan on staying up if only to see some message board reactions.
You can likely hit up the nearest friendly message board to see which of your favorite outlets are live-blogging the event, but I know Kotaku plans to live-blog it.
I really hope it's an info blowout, but I could definitely see them holding quite a bit of info back to use at E3 this June. Are you guys staying up? Leave me a comment and let me know.