These sole pads come in contact with the ground where the majority of your foot touches, saving them from dirt and street grime. The midfoot and arch will still get dirty (this is a fact based on my barefoot running experience) so these aren't totally that smart. Maybe if Nike came out with a full-foot concept design it would gain more traction (no pun intended.)
I am skeptical of the practicality of this new release, but am also encouraged that Nike is taking an interest in minimalism beyond their "barefoot" (read not minimalist by any means) Nike Frees. If Nike or any other shoe company needs a tester for their minimalist products, don't hesitate to contact me. I have a marathon to train for in 2011 and will racking up the miles, mostly in my Vibram Five Fingers.
Oh yea, thanks to Melanie for the heads up on the foot pads. She rocks!