I say its prep for release of refined product
Folks, think about it. You need beta testing and a proven trial ground for your spanking brand new OS. Do you do a public beta? Maybe, but why not do a lowscale beta (wouldnt call this an alpha) based at your own company? MS does this. Hundreds around ms outside of the skunkworks start using the new os in real world environment. Its a great midstep before release of a RC.
Google I would argue is doing the same. Forcing users to adopt the new OS with no dual boot ensures the base is intact without corruption. Purer data and testing. I would do the same thing if I was leading the chrome os rollout.
I admit I have not tried the OS. But if you had reached a milestone in your product development, and wanted to start getting it out there as a polished product, this is a step I would take.
Google gets into some crazy apps, we've all seen them. But their methods stay pretty much along the same lineal path.
