Google has updated ChromeOS overnight, bringing with it Multi Sign In support, Google Drive support in Incognito mode and a host of bug fixes. Curiously, however, there's a few Chromebooks that won't be getting the update right away.
Google's Chrome Releases blog notes the details of the update. There's a number of changes, covering:
Multi Sign in support - Easily use multiple accounts with your Chrome Device New “App info” view in the Chrome launcher Settings appear in a window, not tab Save to Google Drive in Incognito mode Client Certificate Management for organizations using the chrome.enterprise.platformKeys API Managed Bookmarks - Push and manage bookmarks for your organization
It brings the stable version of ChromeOS up to version 37.0.2062.119 and should be an automatic update for most Chromebooks, excluding the Acer C7 Chromebook, Samsung Chromebook Series 5 and HP Pavilion Chromebook. No word on what's causing the delay for those particular models, which will presumably be updated in due course.
Stable Channel Update for Chrome OS [Google Chrome Releases]