In the run-up to, much of the mainstream media talked about prospects for the new devices — calling them not Windows Phone 8 but Windows 8. Is that a confusion that does more good or harm?
Windows Phone 8 has the Windows 8 kernel and some of the programming interfaces, which is why Steve Ballmer said atthat "we bring a developer platform and the Store in a common way to Windows 8 and Windows Phone 8".
The change gives Windows Phone 8 more power under the hood, and the kernel should make developing drivers for new hardware faster, cheaper and more reliable.
They both have a, with notifications "front and centre", as Ballmer put it. Hardware acceleration of HTML5 in IE10 is just as useful on the phone as on the PC and well-written sites will automatically scale to fit the phone screen with a great layout — like the new HTML5 Pulse news site.
What Windows 8 and Windows Phone 8 have in common
And Windows 8 and Windows Phone 8 — and Xbox — share more than an interface Microsoft used to call Metro, although familiarity with the Start screen on Windows Phone makes Windows 8 easier to use, and vice versa.
They also share services. Achievements in Xbox games are the obvious one. There's something addictive about seeing your Minesweeper score from your Windows 8 PC on your phone and getting your perfect FreeCell record from your PC on a new phone gives you that nice warm feeling that's one of the really appealing features in Windows Phone.
As Microsoft is likely to put it, Windows 8 and Windows Phone are better together
It's not just games. The way Microsoft is pushing using a Microsoft account to sign into Windows 8 means you get SkyDrive integration for pictures and documents and OneNote notebooks. Notes you write on a Windows 8 tablet will be on your phone when you need them.
The photos you take on a Windows Phone 8 handset automatically upload, in full resolution rather than as half-size images, to SkyDrive so they appear straight away in the Photos app on Windows 8. Your Bing search history on Windows 8 could make the search results on a Windows Phone 8 handset more relevant.
As Microsoft is likely to put it, Windows 8 and Windows Phone are better together, and getting you to think about a Windows phone rather than a Windows Phone could be the marketing leverage Microsoft needs to start selling more devices, which is about the only thing Windows Phone hasn't been good at so far.
Like your Windows 8 system? Like your Xbox? It'll make you more interested in checking out a Windows Phone, hopes Microsoft.
Related but different operating systems
But while Windows Phone 8 and Windows 8 are related products, they're not the same. That's a good thing. Having Windows on a 12-inch touchscreen is usable, but the familiar Windows interface on a five-inch screen would be a problem. The repeated failure of companies such as OQO proved that. Windows Phone has been an excellent touch interface all along and fits the small screen perfectly.
The real relationship between Windows 8 and Windows Phone 8 is an advantage for Microsoft that might be confusing to explain to a mainstream audience.
Is suggesting that they're the same thing a potential disadvantage? Will it make people expect a complex interface and blue screens on their phones, even though blue screens are rare on Windows these days and almost always mean you have a hardware fault? Or will the associations of Windows 8 have the same halo effect as Mac OS and iOS, which used to be routinely touted as pretty much the same thing despite the massive differences?
Is talking about Windows 8 and Windows Phone 8 as if they're the same thing careless, or just what Microsoft would like us to think? Probably it's both.