Out of curiousity, does anybody know the platform and programming language used to program the Roomba? I'm not so much talking about aftermarket kits but what is used to implement the algorithm at the factory?
Per this link, Roomba's microcontroller is a Freescale (ex-Motorola) MC9S12E -- what iRobot specifically uses in terms of programming languages may be their trade secret, but I believe such devices are typically programmed in assembly and C, e.g. with this kit.