Is Google baiting the competition (with Google glass)?
I've been thinking a lot recently about the potential of Glass to transform the world. Imagine the affect that glass would have on the entertainment industry if, say, a few people with the Glasses were at a concert or movie theater or a few dozen (hundreds? thousands?) had them at a sporting event, if millions could witness a crime or heroic act in real time, or if an entire classroom could share its collective input into one document while constantly accessing the entirety of all information (hell, we wouldn't even have to be in the same room).
Glass could be capturing, collecting, and contributing to the ostensibly all of human experience. So, why would Google allow such an inordinate amount of time for competition to know exactly what they're doing with it? I think it's pretty straightforward, Google doesn't want to be the only ones held responsible.
Much like a lot of Google's projects, it's too ambitious for them to unleash it "spontaneously". They know that the change would be too momentous for them alone to take the brunt for the consequences on pretty much every facet of current human society.
I think it's pretty clear that google is implementing a lot of tools for glass across a lot of its different products: hand-writing recognition in its search apps for iOS and Android, the visual elements of Google+ interaction (as shown in the short google glass commercial), the panoramic function in 4.2, the voice commands in its search app, as well as the predictive and context aware results of Google now.
Google knows it's building something incredibly powerful, possibly more momentous than any other invention in human history. But they're openly inviting the likes of Apple, Microsoft, etc. along to compete with them, because they know that they're going to be most able to use it to its full potential.