I received my Teensy 2.0 board. I ordered it to check that the hardware I am suggesting (for the usb connection) works.
Delivery was very quick, it took a week from the US to my home (France).
The Teensy 2.0 works fine with the CP2102 board I tested in my previous post.
My PC to PS3 usb controller:
I directly soldered the Rx and Tx pins of the CP2102 board on the Teensy. I added a small wire for the grounds.
Note that this assembly requires to be handled with care: if you plug the Teensy, then hold the Teensy, and if you plug the CP2102 board, then hold the CP2102 board. If you don’t do that, each board can be damaged (in the long term) near the Rx-Tx pins.
Warning: this hardware solution doesn’t work with sixemu <= v0.22 because the serial connection doesn’t work at the right speed (v0.23 solves this).