Sony's just announced in Tokyo that the PlayStation Vita will debut in Japan on December 17th, and it'll partner with NTT DoCoMo for the console's prepaid 3G service. Customers will have two choices of connection here: 980 yen ($13) for 20 hours, and 4,980 yen ($65) for 100 hours. Alas, the rest of the world will still have to wait until 2012, but you'll know more concrete dates as soon as we do. For now, head over to our sister site Joystiq for the SCEJ press conference liveblog.
Update: Capcom's Yoshinori Ono came on stage to mention that Ultimate Marvel vs. Capcom 3 would launch simultaneously with the console.
Update 2: Square Enix also announced that the PS2's Final Fantasy X will be remastered for the PS Vita, and it'll be in PS3-like quality. Sadly, there was no date nor demonstration.