February 14, 2014: There is a point at which Chromebooks are considered to be older devices, and no longer receives full support from Google Enterprise team.
Updates will no longer be pushed out to the devices.
Google states, ". . . advances in hardware and technology eventually make devices out-of-date, and as time goes by, we can no longer provide updates to leverage new OS features." Updates are not "guaranteed" past their EOL dates. (You might want to read the page).
This can be significant for those of you who have purchased Chromebooks for your schools and manage them through the control panel. Google also states that when a model is considered obsolete, it will no longer receive full support, and you may find that devices cannot be managed via the admin control panel. It also says you may not be able to use new management features released.
Here's the link