There was a good thread on Cub Linux/Chromixium in the previous forums (here (http://plugintolinux.ca/node/321)). I am really big on this distro, as it looks like a nice hybrid of Ubuntu + Chrome OS. Unfortunately, the developer retired as of May 25 (too busy to maintain it). While the announcement was sudden, he must have been planning this, as he started a foundation a month ago. Until then it was a one-person distro. Question is whether there are enough volunteers for the distro to survive. We may know next week, according to the foundation thread. It would be a shame if it doesn't survive; I really think it has potential.
I don't think Google wants to dilute "Chromebook".
What Google certainly didn't want was a distro named Cromixium being confused with Chrome OS or Chrome. They took care of that by threatening the developer of Chromixium with a lawsuit if he didn't change the name of the distro. He did, and as far as I know, Google was OK with that. His retirement from Cub appears to be related to other things in life, and not further threats or enticements by Google. Also, I seem to recall that there is at least one other Linux distro out there that mimics aspects of Chrome OS, but I can't remember what it is called.
Update. The fate of this distro is still unclear. There is no version yet available based on Ubuntu 16.04, and no update to the 1.0RC based on 14.04. A few regulars are handling the forums, but there is no word on or from Richjack, the original developer, and no commitment by the team he started to assemble to continue on. This is not a good sign, and it would be a shame to see this very good distro go by the wayside.
Worth noting that of the 820 distributions on Distrowatch, only 273 are still active. A sad fate awaits most of them.