I think that's a good way of thinking. In fact, I'd go so far as to suggest that Microsoft ought to be releasing an "Excel Appliance". Much as Google's ChromeBooks are basically browser appliances, Microsoft could have released an "Office Appliance" that booted straight into Office, ignoring the rest of the paraphernalia of an OS and storing / sharing documents in the cloud. It could have created an app-store of Excel plugins. Included Skype and email as part of the mix.
I'd have called it "Surface Excel" and buried the toxic W****** brand for once and for all.
To keep banging on with a very tiresome and repetitive theme, "Windows" as a brand stands for "we wish we were back in the glory days when we just owned stuff by default".
That's not an idea which inspires me as a customer. What does it even mean? A "Windows phone"?
There is just - barely, but just - time for Microsoft to pivot to using Skype as a brand for a cool mobile device / operating system. Skype already is a well recognised phone and communication brand. There would have to be some cosmetic changes to differentiate it from what people have already seen as "Windows Phone 8". But there is an opportunity. (Another year or two like this and M$ will have destroyed the Skype brand so badly that that it won't work.)