I don't know. But what does the Vita even have games wise? They don't monster hunter spinoff. Don't have metal gear, don't have Dragon quest. The biggest thing I can think of is a is the MH spinoff or the FFX remake which is also on PS3.
I know japan likes portables. But I just can't imagine, A MH spinoff or FFX being a significant system seller for the vita. If FFX was on Vita only I could seeing it having an effect like Ocararina of Time Did on 3DS.
I can imagine it only doing a small fraction of the 3DS. I'm going to say 40% of 3DS saless.