Google has just revealed a new Google Glass Explorer Edition of its prototype camera-equipped glasses at I/O 2012. Pre-orders are open today, only for attendees of the I/O conference, and will cost $1,500 for a delivery early next year. As Sergey Brin himself confesses, this is by no means intended to be a consumer product, but Google's keen to get the Project Glass hardware out into people's hands and onto their faces.