Sega announced Phantasy Star Nova at Sony's Tokyo Game Show press conference this morning, a Vita entry being developed by established RPG studio Tri-Ace. Nova is set in the same world as Phantasy Star Online 2, but can be played both offline or in online co-op for up to four players. It's due to be released for Japan in 2014.
Sega also revealed sales of PSO2 are now up to 650,000, with 500,000 of those coming from downloads. The MMO reached 500,000 sales in the summer.