Is anyone aware of any reliable and reaonably recent reports about the market share or user base of the various DAWS ?

I think the top ones are probably;
1) Protools
2) Ableton
3) Studio 1
4) Cubase
 
Not sure about share numbers though

The data that I saw was from several years ago, lbut on Windows Cubase was no. 1 followed by Reaper, followed by Ableton Live, followed by Studio One.  There wasn't a huge install base of Pro Tools on Windows, which surprised me a  bit.  On Mac Logic and pro tools are the big ones.

That figure would be imposible to calculate. Software is delivered digitally so you cannot get the figures as in the past from Retail sales. It would be the companies themselves who would be supplying the data and that data is either privilaged information or easily inflated to make them look better.  
And user voting polls are always way off. 
And does it really matter? 
Use the software you like, or that your friends are using so you can share. If your projects are to be sent off to a pro studio then you might as well learn Pro Tools because, say what you will, they are the standard. 

Cactus Music
 
And does it really matter? 

Sadly right now this will matter to any Sonar user looking for an alternative.
 

It shouldn't, the only thing that should matter is whatever they choose to use does what they want the way they want it, whether it has the most market share or any other ranking shouldn't even come into the calculation.

To me, it should come into it a little. It helps me feel whether a product is going to survive or not.
If it has a huge userbase, I can feel more confident that it will profit, survive and be improved with time and user feedback and support.
Are some of us not learning this lesson right now? I had aspirations to use other DAWs in the past based on preference of UI, but went with CW because of their long heritage, a kind of nostalgic sense of loyalty, and of course it's a great DAW.
Had I not dug deeper though.. etc.

Right now the DAW I want to use is SONAR Platinum. I have no plans of changing. I've spent enough money on Cakewalk products up to this point to last a Lifetime. Obviously, in my case, market share really doesn't matter, because as of last Friday, Sonar's market share can only decrease.

Matron Landslide
It shouldn't, the only thing that should matter is whatever they choose to use does what they want the way they want it, whether it has the most market share or any other ranking shouldn't even come into the calculation.

Yes, I agree with that, but market share tells you a few things too, such as 3rd party support for hardware and other software, user base and community size for getting help etc. 

Cakewalk Soft 143k
Presonus 218k
Pro Tools 140K
Avid 185K
Steinberg 203K
Ableton 622k
Ableton Live 253k

Lol this is the facebook fanbase of these official facebook pages.

This can by no mean help us know the market share but these numbers do matter. Ableton Live is for sure having a huge userbase. Protools despite low fanbase is used a lot by pros and is sold along with Avid Hardware. That makes lot of profit. Ableton also sells hardware controllers. So I guess Ableton and Pro Tools has huge market share. 

Presonus so doing well and they are good at selling hardwares as well. They must be making very good profits. 

Cubase is heavily priced and still has long standing followers. Steinberg might not be doing excellent business as Ableton and Protools but I dont think they will go down anytime. If at all any such situation occurs I am sure its loyal millionaire producers will fund it. 

Despite not covering the huge mac userbase cakewalk was hugely successful. They weren't doing excellent in the market but they were doing fine. The problem is they had no expensive hardware to sell along with it to make business. And very unfortunate to land in the hands of Gibson