Looks like they've started sending out the Vita beta selection emails, I'm in!
Title of the mail is "『ファンタシースターオンライン2 クローズドβテスト』ご当選のお知らせ" and it contains a PSN code.
It will run from 15.01 to 26.01 (the dates can change).
From a Neogaf member named, Keiician. http://www.neogaf.com/forum/showthread.php?t=502593&page=2
If anyone on this site gets in, can you let us know if the Beta plays over 3G and how well it plays?