The robot experts at iRobot introduce the Gutter Cleaning Robot Looj.

The iRobot Looj cleans an entire stretch of gutter from one location, reducing the number of times a ladder must be repositioned and climbed during gutter cleaning. The 2.25-inch high Looj drives under gutter straps propelled by a three-stage auger that dislodges and sweeps out dirt, leaves and other debris that can cause costly water damage, overspills and ice dams.
You can see the iRobot Looj in action in this video.
The video shows that the Looj does clean your gutter. A couple months ago I did in-depth research on how I can solve the gutter cleaning problem on my house. It is scary to go up there twice a year with the ladder and clean out the gutters. I found a very simple and effective solution with the Marley Leaf Guard (site). Marley's poly-net leaf guard system keeps leafs out of the gutter and because the net tube is round leaves dry and are blown away with the next wind. See photo below.

So yes if you want a 'toy' robot to clean your gutter get the Looj. If you want a very affordable hands-off solution to keep your gutter from filling up with leaves install the leaf guard.

The iRobot Looj starts at $99.99 with the basic Looj 120. The top model (Looj 150) sells for $169.99. The Looj sells direct from iRobot.