If you found the old Scooba difficult to use, iRobot says the 390 has been upgraded for better performance and 30% longer battery life over its predecessor, the 380. All the parts you need to clean are now clearly marked, and when the robot's done mopping, all you need to do is remove the tanks, open the dirty-water port, dump out the water and rinse.
iRobot says the Scooba is actually better for your floors, since it only cleans with clean water -- as opposed to a regular mop, whose bucket of water gets dirtier and dirtier the more you clean. It can do that via a cleaning system that simultaneously preps, washes, scrubs and squeegees different parts of the floor beneath it. No need to sweep beforehand -- the Scooba is designed to wipe up everything.
If you're worried about your rugs and carpets, the Scooba is programmed to avoid them, and once you let it loose, it'll clean every part of your floor multiple times. Even better, it cleans beneath cabinet edges and underneath tables and chairs. It'll also avoid rooms you tell it to, and a "cliff" sensor prevents it from falling down the stairs. It costs $500, and you can order one now.
While the 390 is meant for larger spaces, its little brother, the Scooba 230 is there to scrub those hard-to-reach spots, like behind your toilet. Along with the release of the 390, iRobot is expanding the availability of the 230 to Europe, Africa, the Middle East and Latin America. Dirty floors of the world, take heed.