Marshall

• Even if Sonar continues to work, or is recused, I still think it is a good idea to be fluent in two or more DAWs

If Sonar is rescued and you revert back you could always use Studio One Pro as your mastering environment.
 I purchased S1P a year ago to use just for mastering, to replace CD Architect, and to have a "spare" daw, just in-case.
Now I am starting my new projects in Studio One and will not use Sonar for any new projects until it has a new future.
 
 

Marshall
So, I have decided to jump now and buy Presonus Studio One. I was completely shocked by Cakewalk’s announcement and really didn’t see it coming – my intention until that point was to stick with Sonar Platinum forever – it did everything I needed and a lot more, it was stable, and above all of course, I know it pretty well and therefore it rarely, if ever gets in the way of the creative process.
.
.
. 
But for me, and I am only a keen hobbyist, the sooner I accept that the world has changed and embrace a new system, the better. I’ve jumped now because:
 
 

• I’ve seen enough training videos of Studio One to know it will do everything I need it to do (I am mainly audio, but certainly enjoy dabbling in Midi)
• A lot of the workflow looks not a million miles away from Sonar.
• Some of the SO videos have made me go “wow”, I could use that! It may be that Sonar could do the same, but using a new DAW may actually spark some extra creativity (when I’m not scrabbling up the learning curve). Whilst I am sure there will be frustrations initially, in some ways it may be a breath of fresh air.
• The quality of the training material seems top notch. In particular, I think the Eli Krantzberg Groove 3 course “My first song in Studio One” will get me up and running in no time.
• I picked it up for $169 through Audio Deluxe – yes, I know it might be cheaper next week for Sonar refugees, but I wasn’t 100% sure we would know the crossgrade price before the BF deals finished. In any event $169 for a top notch DAW is incredibly good value.
• I’ll admit I have not researched the bundled effects and instruments but I have a battery of externals – mainly Waves – so this was not a big consideration for me.
• Even if Sonar continues to work, or is recused, I still think it is a good idea to be fluent in two or more DAWs! 
  
  

My situation and line of thinking was virtually identical to yours, and I also purchased a copy of Studio One Pro.  I my case, I remembered at the last minute that I had a copy of Studio One 3 Artist that came with a PreSonus AudioBox iTwo sound module I purchased a few years ago for use with guitar amp modelling software on an iPad.  I had never even bothered creating an account and registering it, but once I did I was able to get an upgrade to Studio One 3 Pro for $149 with the Black Friday sale.  I couldn't see any way their SONAR crossgrade deal is going to be better than that.  Their normal crossgrade prices are $299, and their normal upgrade price from Artist was the same without the current deal.  Even if they knock another $100 off, it will only match the current deal for purchasing a full copy.
 
So, anyone who purchased a PreSonus sound module any time in the past few years, check if you may have an unused copy of SP 3 Artist included that will get you an SP 3 Pro upgrade for $149 with the Black Friday deal.