Interesting times are ahead with major alliances forged a long time ago not really breaking up but becoming non-exclusive. Windows and Intel have been a team in the PC world for decades but have so far failed to establish themselves in mobile. But both desparately want to be in that domain. It seems they have figured out they can't do it together as a dream team, they each need to partner with an established player in mobile that helps with their established success.
Intel with Android
So we have Intel who seems to have finally been able to produce a chipset that is lean enough for a mobile phone (see here, here and here). Their acquisition of Infineon for a 2G, 3G and 4G mobile baseband also helps tremendously. By adapting Google's Android to their chipset they have a great smartphone operating system from day one and it seems that all apps that do not directly access the hardware (i.e. everything programmed in Java, i.e. pretty much all apps except games) will run on Intel based smartphones. Not bad.
Microsoft with ARM
And then there is Microsoft on the other side. They've waited for years for Intel chips to make their OS run on tablets and other gadgets but it never worked out so far. So I guess they have lost patience and have now ported Windows 8 for ARM to run on tablets. Interesting technical insights can be found here.
Intel with Windows on Mobile?
Perhaps Microsoft will consider Intel chips for their tablets again in the future should the afore mentioned Intel/Android project work out and Intel keeps churning out good mobile hardware platforms. And this Intel project, unlike the previous attempts over the past few years, looks quite promising. The advantage for Microsoft coming back to Intel is that running on an x86 architecture would remove the need to recompile Windows applications for ARM (unlike apps on Android which are always "just in time" compiled).