I'd like to see the context of that Kaz comment.
I think it probably actually went something like this. "Will Vita take as long as PS3, 3 years, to become profitable on hardware?" "Kaz: (laughs) No, it will take less than that"
Which isn't the same as 'it'll take 3 years to become profitable'. IIRC he, and others at SCE, also said that at the very least, as a business (software+hardware), it would be profitable from the start.
Yoshida seems to be saying that they are aiming for hardware profitability, and though he can't give a certain answer right now, that's the projection.