The first day keynote of Google IO is in the can, and we certainly got some exciting news on the next iteration of Android, as well as where Google is taking the platform this year. The Nexus 7 tablet is up for sale, as is the Nexus Q, but what's really exciting is a developer-only offer for IO attendees. That's project Glass.

The Project Glass explorer edition was demoed by Sergey Brin in a heart-pounding skydiving video featuring a 4-person hangout, which we've posted below.

If you were concerned that Glass would turn out to be vaporware, you can set those concerns aside for now. Google has announced that US-based IO attendees can now pre-order the first version of Project Glass to get a start on crafting apps and features for the hardware. The first product will ship to purchasers in early 2013, with a focus on bleeding-edge development. Brin made sure to note that this is not a consumer product. This is only for those that want to be on the front line of next generation mobile development. The cost to get in on the program: $1,500. The U.S. only restriction is due to regulatory concerns in other countries.

The initial product is described as weighing less than a typical pair of sunglasses, comes with a touch panel on the side, a button on top to take photos and video, and transparent screen for information. They sit just above a normal person's field of vision, so as not to interfere with regular eye-contact.