Will this stem be the answer to what riders want? When I first saw this, I immediately had flashbacks to the Girvin Flexstem back in the 90s. That stem had an elastomer bumper to provide bump dampening (but no ability to control rebound). This stem, from Sta-Fast, is an air shock that is adjustable. The idea is that the rider would be comfortable without the expense and weight of a suspension fork. All anyone wants is to be comfortable but fast on their bicycle.
Check out the video from Sta-Fast to get the low down on the new stem that seems to improve on the old bumper stem. It looks like they offer a stem for road, cyclocross, and mountain bikes. Time will tell if this is something worth putting on a bike.