The upcoming Xperia Play, former known as "Playstation Phone", will be quite different from the Playstation Portable, at least according to Sony. They don't want to create confusion between the two, and don't want users to believe they can actually exchange one with the other.
Here's what their gaming chief, Kazuo Hirai, has to say about it:
We don't want gamers to be asking, what's the difference between that and a PSP, we have to come up with a message that users will understand. It would have to be a product that keeps the PlayStation's strengths intact.
My guess is that they want the Xperia Play phone to be simply the "best gaming Android phone" and nothing more. Of course, that's a pretty tall order, and they plan on doing that by attaching a physical gamepad to the phone.
But the question remains: will the Xperia Play phone have a dual core chip with high performance 3D graphics like a Tegra 2? Something tells me it won't, and I fail to see how it could still be called the best gaming Android phone, when other phones will be able to play much richer games. The physical gamepad can only help so much.