Glass is an entirely new kind of device; to have good ideas I think we need to wear it and experience the world through it. The API is fairly constrained, but so is the device (eg always in the field of view). And strict constraints, when enforced for good reason, often lead to interesting products (eg Twitter).
See the work of Prof. Steve Mann, specifically "EyeTap". I understand one of his ex-students is on the Glass team, however "an entirely new kind of device" it is not. It has a heritage of ideas and implementations that are around 30 years old.
That's true, but Glass is the first time something like this has been mass-produced. It's clearly a version 1 product, even though there have been other people doing similar stuff before glass.
