For businesses, Chromebooks aren't about what you get - they're about what's left out. The knee jerk response is 'the operating system' (it's Linux underneath but you'll never see it) but the omission that appealed to most of the businesses talking up Chromebooks at Google IO is complexity. With no locally installed apps, just Web apps and streamed virtual apps from VMware or Citrix, and hardly anything that the users can configure or change, there's not much to go wrong or get confused by. Of course if you want the same functionality and power of rich applications you're just migrating the complexity into the infrastructure (for virtualised applications) or the Web server (for Web apps), but it would be easy to argue that's where any complexity should be - in the hands of the people who get paid to put up with it.
Google's TCO calculations compare Chromebooks to a completely unmanaged desktop; Microsoft uses those same Gartner figures to push System Center and MDOP and Windows InTune (and Dell uses them to lease you managed notebooks). If you're going to virtualise applications to run on Chromebook you could get many of those advantages by virtualising them to run on Windows (and I expect the vast majority of businesses that use virtual apps on Chrome will be using them on a mix of platforms courtesy of Citrix or VMware). If you're one of the companies with 60% of your corporate data on the desktop rather than the server, you can use group policies to stop that without abandoning the idea of local storage.
You can do VDI and roaming profiles and folder redirection and group policies and desktop optimisation with Windows - and you can chose between umpteen different tools to do that, which may be a plus or a minus depending on how you view it - but usually it's a struggle to get users to accept locking down systems, and when you have a complex and unmanaged desktop environment it can seem like it's easier to throw it away and start again (as the old joke puts it, I wouldn't start from here). But while I might complain if you put a thin client with no YouTube access on my desk, Google has managed to make thin client look sexy by dint of packaging it as a laptop and taking advantage of the fact that a lot of what users want to play with is on the Web now.
The message of IE9 and IE10 (and, I predict, at least some of the message of Windows 8) is about the Web being better on (a not-too-elderly version of) Windows, plus all the rich apps you know and love. Is Windows itself something you love? Chromebooks should be sending a message to the Windows team that for users, Windows just can't be ugly or complicated any more. A lot of Windows 7 is easier to work with but dig deep enough into a control panel and you'll find a dialog box crammed with checkboxes; in IE9 that's one click into the Internet Options control panel. Anything marked Advanced is likely to be a dialog that would look at home in Windows 2000; it's like falling back down the rabbit hole. And that's assuming you know where to find the tool you need. Quick, how do you change the width of scroll bars in Windows? Of course it's obvious that you start by clicking the link in Personalization to change the window colour and then choosing Advanced appearance (er, not - and in that case searching the Start menu or control panel doesn't find the tool for you with any search keyword I can think of).
I recently turned on a new notebook that came with a long list of pre-installed software and had over 80 processes running; dealing with all of them would still involve delving into the notification area, the uninstall programs control panel, individual app options, the startup folder and probably the Registry (or at least the nifty Sysinternals Autoruns tool). That's a rich set of options for developers and power users to take advantage of - or a really confusing set of options to have to learn your way around. Of course, in the Chrome browser I can't even find a way to choose not to put the URL on the bottom of every Web page I print, and I don't think taking away all the tools is the answer - but the experience can be a lot nicer than this.
One size does not fit all; but finding your size in the racks of a badly organised discount store full of screaming toddlers (or a quirky department store that's added a lot of different rooms and galleries and collections over time; complexity doesn't equal downmarket) makes it tempting to go to a shop that only has baggy pants that you can tighten with a belt as necessary. Sure, the expert shoppers can make a beeline for the right shelf, but too many Windows users have to hunt through the interface experience of a rummage sale.
I don't care how deeply buried some of the options and dialogs in Windows are, too many people still have to face them; shouldn't that heritage of nested hierarchies of multi-tabbed dialog boxes be retired in favour of something simpler and better organised? Adding the ribbon to Explorer might help; and by that I don't mean slapping five buttons on a ribbon with a link that brings up the same old Folder Options dialog - I mean making sense of all the options and making them easy to work with. The excuse of not having time or resources to work through the entire interface is a problem for the Windows team to solve, not something for users to put up with.
Chromebooks do a tiny fraction of what PCs can do - but they do it with a fraction of the complexity users have to deal with on too many Windows systems. Windows needs to keep the power and lose the complexity.