While the PSP continues to sell well in Japan, game site EDGE has a piece up on third party devs leaving the PSP platform. From the piece:
Without a killer app in the West on the level of Japan's Monster Hunter series, the PSP may just be crowded out of a competitive marketplace, an appealing piece of hardware people buy and never use.
There's data and numbers, too! It's not all gloom and doom. Here's the irony: "The numbers here show PSP hardware sales are growing at a steady clip every year, which is the proper behaviour for a healthy platform." So there you go.
Third Parties Abandoning PSP [EDGE]