To add to the Linux discussion here...
At this moment Linux is very capable of running DAW's. It has it's own low-latency drivers (Jack), and there are several distributions that even give you an special low-latency kernel.
There are also commercial DAW's available for Linux. The most well known at this moment is Bitwig. I tried the demo on an standard Kubuntu distribution (14.04 LTS), and it runs great and fast. An lot of sound-cards are supported (I used an M-Audio Delta Audiophile 192k in the test), and an lot of plug-ins just work without any problem using wine (there is an special version in development called "Airwave" that is an real fast VST bridge for Linux - it works for the majority of VST plugins). So yes- it is perfectly possible to use Linux as DAW platform.
On the idea of Windows subscription. I really don't know how this will turn out, but I have no real positive feelings about that. Let me explain...
When "renting" software (like Adobe), the programs stops working if you stop paying the monthly/yearly subscription. That is not great, but you can use an alternative to get at least some work done. The same goes for Office (you can use the free LibreOffice.. yes it has it's limitations, but you can get work done with it).
With Windows, however, you are in an whole different region. Windows is no program, but the platform where all your data and programs reside. If Windows stops working because you did not payed the monthly/yearly fee, you lose the ability to access your data and run you (expensive) programs. Most users would not know about alternative operating systems, so in effect Windows would turn into an form of "ransomware" (if you do not pay, you loose everything).
I do not think Microsoft would turn Windows into an real subscription platform (the backlash would be huge), bit IF they do, they have an very powerful way to force people into payment. As said - I don not really think Microsoft would do something like that, but at the other hand... I have seen Microsoft do worst things..
It will be interesting to see how this all turns out to be...