Not only that, but the market has not been established either. The product has not real solid use case except getting Facebook/G+ notifications on the go.
Head mounted camera is only of use to a niche of users. Walking/biking directions can still be seen on a mounted mobile on bike and mobile in hand/voice directions on headphones. Augmented reality is not a specific use. There are not many things that augmented reality can be used on in real world by casual user right now. And there won't be any until someone (like google) creates it.
