It's all over the net, Google is dumping MS Windows for desktops and dictating to use MacOSX or Linux instead, for those who still want to use MS Windows, an exception request needs to be filed. I know it is the other way around in a lot of companies.
Is Google mad or genius? Well, no doubt i think they are genius and i think it is an important message they are sending out for others. The main reason why companies are not migrating away from MS Windows is that the cost of moving to another platform is too high. First of all, this is a one time cost and you need support for MS Windows desktops just as well.
Secondly, nobody ever calculates the cost of all the extra software you need to install onto it to keep MS Windows secure, neither does anybody keep in mind the huge cost and public image loss associated with a security problem in your company. And the fact is they will happen despite all the extra security thrown on top of MS Windows.
Ofcourse Google will have it easier then certain other companies who have a lot of MicroSoft services running in their org, which most probably will not work decently on other OS/browser combinations besides MS Windows+IE (simply think Sharepoint or certain Office documents). However that is not a reason to keep paying MS-tax or leaving your company open for potential high security related costs.