Google+ is dead, just like Ping is dead. The "plus" is just a social network on top of Google products. Ping is a social network on top of iTunes and we know how well that went. People don't like "antisocial" social networks.
Sure, this might work. But the extra pixels needed for the bezel will consume battery with current technology. Also, a new kind of proximity sensor have to be developed for these use cases. It will be really annoying to set the virtual bezel manually all the time.