I spent a good amount of time working with Brillo when Google was first pushing it. The thing I liked most about working with it was the system they had for OTA updates. Even in beta they had support for staged rollouts with some analytics on the rollout. There was lockin with the solution as updates used Google's cloud and was signed by both your and their key, but it was a really robust system considering how new it was.

I really hope the project gets more attention. Not only was the firmware update system nice, but having the promis of having the core OS managed and only having to worry about your application was nice as well.