Sega teasing new game for PS3 and PS Vita

Sega recently opened up a teaser site that says that a new project for the PlayStation 3 and PS Vita will be announced on March 28. The only clue we have is slowly dripping sand. Could it be a new Valkyria Chronicles game? With the industry's trend of remakes and sequels, my bet is that Sega is releasing Valkyria Chronicles III to the west. However, it'd be pretty neat if it were a new IP.