Yoshida stated that Sony plans to allow the PSP and the NGP to co-exist on store shelves. He added that the NGP "can't replace a platform that has already been on sale for seven years now."
The unasked question is, of course, "Why not?"
He claimed "In terms of pricing, we can't sell the NGP for the same price as a PSP. I think the NGP needs time to mature and get adopted by users. So, for the time being, both platforms will coexist." The PSP 3000 is currently at $170 USD, so it's obvious that they can't sell the NGP for that - the question is, how much more?
This is the same strategy Sony used when the Playstation 3 was released. While Microsoft and Nintendo discontinued the Xbox and the GameCube immediately to make way for the Xbox 360 and Wii, Sony continued to sell the PlayStation 2 at a cheaper price, along with the (at the time) expensive PS3 console.