The user interface is controlled through speech, and additionally through what appears to be a small trackpad on the side of the device (for silent operation). The user interface itself sits at the top-right of the visual field and... Well, just watch the video.
So, what kind of people are they looking for? "We’re looking for bold, creative individuals who want to join us and be a part of shaping the future of Glass. We'd love to make everyone an Explorer, but we’re starting off a bit smaller. We're still in the early stages, and while we can't promise everything will be perfect, we can promise it will be exciting." You have to send in an application and so on, and it's unlikely any of us regular folks would ever be able to get into the program - especially since, as usual, it's US-only.
Still, this is so much awesome.