do you think both platforms will get discontinued next year or something?
No. Vita will reach less than 20million. Maybe 17.5
3DS will Reach less than 65million Lets say 64million.
PSP is still selling, and as we saw with PS2 it will still receive a fairly large shipment to end its days. It will end its days with 83million shipped (More than GBA)
PSP Lifetime more than PSV+3DS Lifetime.