Well, I was thinking more along the lines of using it for homebrew and emulators. Just think how cool it would be to be able to play N64 games like SSB with three other people using just one PSP. But impossible is impossible.
As far as I know and all emulators I have played "NeoGeo, MAME (CPS2), Sega, NES", none of them had the option to configure a player2 or player3 buttons, it's all about single player
even with emulators, some has WiFi multiplayer compatibility, but still multi-tap won't serve
any good here.
but, i think, if those drivers were released, there will be developers who'll make homebrews
supporting the multi-tap