The beat from the Silicon Valley drums has been that Microsoft is doomed because Windows is a PC operating system, phones outsell PCs, and Windows has struggled on mobile. QED.
It's true that Windows phones have lost market share – and that Microsoft is starting from zero in terms of market share on Windows Phone 7, an operating system that's not actually Windows as we know it and not the earlier version of Windows for devices, Windows CE.
On the other hand, devices are portrayed as the manifest destiny of Linux and open source. The current and anticipated success of Google's Android has helped reinforce this perception.
But this week, Microsoft and Linux did all but nod as they passed each other going in opposite directions.
Windows Phone is becoming Nokia's primary smartphone platform at a time when Nokia remains - just - the world's largest maker of such phones. Linux crossed over to PCs as Hewlett-Packard said it will ship laptops and desktops on webOS, the Linux-based operating system it now owns. HP is the world's largest PC maker and was - at least until recent times - Microsoft's biggest partner on Windows products and services.
But the grass is always greener on the other side, as both camps are about to find out.
Microsoft has just bought market share with its allliance witih Nokia, but it's a shrinking market, and there's a question over how much this deal can really help Windows. It might even make things worse for Nokia.
The first hurdle is engineering. Until now, Microsoft has kept tight control on the handsets running Windows Phone 7, to make sure the phones don't fail. But Nokia is a rat's nest of form factors. To try and get around this, the companies have said Nokia will contribute its expertise on hardware design and language support to put Windows Phone on a larger range of price points, market segments, and geographies.
But there's another problem.
Microsoft will have to rely on Nokia's engineering heritage to get Windows Phone working on its many and varied handsets, to make sure phones work and don't get a bad reputation for performance or reliability that'll damage its market share further as consumer turn off. Yet, Nokia has no experience of Windows Phone 7. Iit wasn't even in last year's original OEM line up.
A real problem for Nokia will come in actually keeping the engineering expertise it's famed for and will rely on.
Nokia's going all in with Microsoft, after spending years trying to avoid Windows. It joined and bought Symbian, hooked up with Intel on MeeGo for mobile Linux, and bought the Qt cross-platform brains. That means Nokia has now got an army with completely the wrong skills. They'll need to decide who will be retrained, will be cut, or who will simply decide to leave for new jobs. Nokia's engineers have already shown what they think of the deal.
The rub? Nokia might actually be forced to rely on Microsoft, a company with comparatively little experience in handset engineering. According to the companies' announcement, Nokia will at least have input into the Windows Phone roadmap. How much influence it has will depend on Microsoft, and its joint ventures in software have never been particularly successful.