Many have tried to challenge the iRobot's dominance in the brain-dead floor-cleaner space, but with 2 million Roombas sold in 4 years, it doesn't look like the cute little vacuum is going anywhere anytime soon. Now Evolution Robotics is teaming up a unnamed large appliance manufacturer to take robot subservience to new heights, and hopefully knock the Roomba down a notch while they're at it. They're touting their "NorthStar" navigation system as a key differentiating factor, which involves wall units that project an infrared pattern on the ceiling, allowing the bot to orient itself and therefore clean more efficiently. Of course, NorthStar is already present in the eVac robo-vacuum available from The Sharper Image, so we're guessing Evolution Robotics is banking on the brand caché of their "large appliance manufacturer" to get the forthcoming bot a bit of recognition. Evolution products have been quite successful in other arenas -- their navigation systems power WowWee robots, along with Sony's now defunct Aibo. They're also working with Korea's Yujin Robotics to power the "Jupiter" household bot prototype, pictured above. Of course, iRobot isn't just sitting back and counting the cash -- they've hinted at improved navigation for the Roomba as well, and who knows what they'll have on the market by the time Evolution's vacuum bot hits retail in 2008.