It’s now been a year and a half since the Google Glass’ first round of Explorers paid US$1,500 to be beta testers. The actual devices were first handed out earlier this year, but effectively most developers haven’t had more than six to eight months with the thing.

And yet, now Google has made two announcements about Glass: They’ll be tripling the number of Explorers, and they’ll be reinventing the hardware. Existing Glass Explorers have just a few days to name three friends or acquaintances who would be appropriate developers to test out the device.

(Chronicling the experience of Google Explorers)

If your invited guests are chosen, they’ll be offered a chance to pay $1,500 for a Glass. Existing Explorers, on the other hand, will be able to cash in their device for a new hardware revision, free of charge.

It’s all movement that I’ve not seen in a hardware rollout before. Indeed, it’s the sort of strategy we see more often in software than in hardware. Games have done this a lot more since the advent of Minecraft: There are a ton of alpha games you can purchase now, paying less than the eventual retail price. The idea is that you’re so excited about whatever this thing is that you’re willing to pay for it, and still not have all the features and reliability the thing will eventually offer.

But seeing that in a hardware platform is unique. It’s not so easy to update hardware, though the software inside can be updated easily. I think Google is finding out very rapidly that its hardware needed to be constantly evolving to keep up with the flow of wearable tech in the pipeline.

When Google introduced Glass last year, the industry was agog with excitement and ideas. But a year and a half is a long time, and there are now dozens of imitators and also-rans in the works. Some devices, like the CastAR, aren’t even like Glass, but rather take it in a new direction.

(Microsoft already testing a product to compete with Glass)

That’s the kind of movement you would want to see from Google, if you were a Glass supporter. But if you’re just a developer wondering which of these devices you should support, there’s only one thing you want to hear right now: standards.

But standards are a long way away. For the next few years, at least, you’re going to have to pick a platform and stay with it. Glass is a unique case, especially since it’s entirely hosted out of the cloud. There’s no familiar development platform to build on there. Elsewhere, with CastAR, Oculus Rift and others, the device plugs into a PC, and thus you’re building in Windows.

All in all, Google’s slow movement in rolling out Glass is going to be an interesting experiment in multi-year, transparent hardware development. In a few years, those initial Explorers with Glass 1.0 will probably covet their device as a rare antique, versus the new and shiny they could have upgraded to. And the consumers will still be scratching their heads and looking at all these things wondering, “Where’s my killer app?”