Famitsu: 64% of Japanese players plan to buy PS Vita this year.

[DirtyP2002]

34.6 million gaming devices were sold in Japan. (360 + PS3 + Wii + 3DS + PS Vita) Not counting PSP, WiiU and DS.
So there are 34.6 million players.

So, 64% means 22.14 million PS Vitas will be sold in Japan in the next 12 months. Seems legit.