PSP's launch was ha-uge. And obviously not reflective of ultimate marketshare.
PSP: 185k
PS3: 165k
3DS: 113k
Wii: 105k
DS: 87k
360: 70k
Vita's probably on the lower end of the launch numbers here judging by software, but probably not extremely low. 70-100k seems 'normal' based on the above, PSP and PS3 were kind of outliers.
I was guessing the psp was kinda huge. I have loads of people here at work who have no interest in the Vita or 3DS but they all bought the PSP.