I'm waiting for a Palm Pre (comes out in the fall in Canada), but then again there are a number of phones coming out around the same time using Samsung's Snapdragon platform. Basically, you get a dual core 1Ghz ARM CPU and a powerful mobile GPU (22 million triangle/s, 133Mpixel/s). This is well beyond PSP class horsepower (which has larger theoretical values that cannot be achieved). Specifically, I'm thinking of the HTC Thoth 100, though the Asus F1 and others have similarly outlandish specs.
Still, I will probably go with the Palm Pre anyways, as it will certainly be more affordable and is still very powerful.
Either way, I can't wait to start programming some 3D graphics on one of these things.