I realize that. My point was that lots have done it the direct connected way, but nobody had gotten it to work 100% yet through the serial port.
If your confident enough to solder all the wires, the direct connect way is probably going to be easier for you.
If you know how to program, and can write the code for the pic as well as the plugin on the psp to make it work, then this way may work for you. But the average joe with just basic knowledge of code won't be able to do this.
I think this way, through the serial port, would be much nicer to overall ease of use once it's finished and working 100%. Especially since you can also use wireless controllers.
That's all I'm sayin.