The iEraser attempts to fix that. It is a handheld block with a special microfiber surface. It is very reminiscent of a whiteboard eraser, by design. You firmly drag it along the screen of your iPad, removing smudges along the way. The iEraser is almost the size of an iPhone, so you don't have to wear out your arm cleaning the entire surface of an iPad. My iPad takes a beating, so I took some photos before, during and after cleaning it with the iEraser.
I saw a preview of the iEraser at CES, and it will be available to the public on February 15th. It will be available in black, white or pink, and is made in the USA.
I would prefer that it came in a drawstring bag or a box because you don't want it to accumulate lint or foreign objects which could scratch the tablet.