Peter Bright at Ars Technica is wondering how many operating systems (OSes) Microsoft actually needs and, for that matter, how many they already have. Three consumer versions of Windows exists (or brands of it does): Windows RT, "full" Windows, and Windows Phone. Then again, it is really difficult to divide up what a unique operating system even is. All of the aforementioned "OSes" run on the same base kernel and even app compatibility does not align to that Venn diagram.
In my personal opinion, it really does not matter how many (or what) operating systems Microsoft has. That innate desire to categorize things into boxes really does nothing useful. At best, it helps you create relationships between it and other platforms; these comparisons may not even be valid. Sure, from the perspective of Microsoft's marketing team, these categories help convey information about their products to consumers.
… And if recent trends mean anything: very incorrect and confusing information.
So really, and I believe this is what Peter Bright was getting at, who cares how many OSes Microsoft has? The concern should really be what these products mean for consumers. In that sense, I really hope we trend towards the openness of the last couple Internet Explorer versions (and of course Windows 7) and further from the censored nature of Windows RT.
You can have 800 channels or just a single one but that doesn't mean something good is on.