These are good news for the Gentoo community. Portage is being used to build Chromium OS packages. As you may know, Portage is the Gentoo Linux default package management system which has its roots on FreeBSD's ports.
As of February 5, Google developer Ryan Cairns has made this statement on the Chromium OS dev mailing list:
As we’ve been growing and working with more partners, the need to support board specific builds and improve our tools has become more urgent. In order to get there more quickly, we’ve been investigating several different build tools. We found that the Portage build tools suit our needs well and we will be transitioning 100% within the next week.
As a Gentoo user and supporter, I'm happy to see Portage being picked by major projects like the Chromium OS. Hopefully, it will bring more (positive) attention to Gentoo and maybe we will see the Google folks contributing with improvements and bug fixes back to Portage.
For those interested in checking out the Portage-based build environment and build a bootable Chromium OS image take a look at this Chromium OS documentation page.
If you are interested in Portage features and usage check the Gentoo Handbook page about Portage. And if you got curious about Portage history I recommend the this article by Daniel Robbins, the founder of Gentoo.
To know more about the Chromium OS project and Google Chrome OS check this.