All of your hardware Belongs to US....
when they sort out the Software as a service they will have it cracked. and will get back on more devices if only by being a second tier on the installed OS.
Im my household there are a number of devices 4 x windows 7, two x android, one x IOS 7, and one x OSX 10.6.
with VDI licensing and per user we will be able to have VDI accounts with a supplier (may be even Microsoft themselves) we will be able to access our sessions from any of the devices and hopefully upgrade and down grade the ram, storage and software as needed (for a fee of course). and all this as potential as an end user,
(Microsoft Home server, with centralised MS software library, for VDIs, Media Centre server, Network storage, and Home Automation ;-) just a suggestion but as its NON cloud it wont happen........)
The more people using Microsoft software even if run on top of another OS the more sales. at the moment an IOS, Android or other non MS device is a lost sale, with this there is potential of keeping those users as Microsoft user and keeping some market share and relevance in "This post PC world".