So far, I haven't heard anything. I believe they're still doing some tours in Japan right now. When they announce to do a US/overseas tour, they will release the information through their English (and Japanese, I think) newsletters, which you can subscribe to from the English part of their official website (and the Japanese one for the Japanese one).
I'll be very excited to see them again, and hopefully they'll come to North Carolina like they did during their concert tour before the one last year. I have CDs and the Absolute POLYSICS Book for them to autograph, and of course I have a lot of love to shower on them
I don't post here much anymore but I still have a fond appreciation for Polysics. Hit me up on Twitter @west_haven if you really wanna talk to me