The I/O board in the belly contains:

48-pin Toshiba TMP86FH47AUG 8-bit microcontroller.

Two ON Semiconductor (formerly Fairchild) FAN8100N low voltage 2-Ch. motor drivers

Texas Instruments LM324 quad operational amplifier

If anyone has any more information about the components inside Pleo, let us know and we'd be happy to post more information here.