"Use a Chrome book to access a Windows share? Why not just run Windows and be done with it?"
One of the reasons we are now a Linux shop was it was a lot easier to get Kubuntu working with Windows Shares than the new fangled (at that time) Vista. Has anything changed?
Yep, lack of Samba support, is a major limiting hole on my Chromebook so this is great news. Could end up with ChromeOS eating into the thin Linux client market as well as Windows.
But the TL:DR on the road answer is probably 'boot time'. Who needs it?