It's really not a matter of "if;" it's a matter of "when."
Sony's next-generation portable is…well, exactly that- the Next Generation Portable, which is scheduled to launch later this year. The future is not the PSP Go, which Sony has admitted was more of an experiment than anything else.
The handheld unit that subsisted entirely on digital software will soon go the way of the dodo, but perhaps it has already happened: according to a blog post by a Japanese Sony Shop employee (as reported by Andriasang ), Sony has halted production of the PSP Go. On top of which, it seems the Japanese Sony Style store doesn't stock the portable gaming unit anymore, although the American branch still has it listed for $200. From the start, the $250 price tag was questioned by those who wondered what the PSP Go had to offer.
As for the NGP, it has been receiving much rosier feedback from gamers, analysts and developers. Good thing, too; it is the future, after all.