This is really sad news. Sonar's been a godsend for me really, with it's monthly subscription payment option was the only way I could afford a decent DAW at the time.
I feel bad for the Cakewalk employees who've put their heart and soul into the products.
I also feel bad for those who purchased lifetime updates, who probably now feel just a little bit mugged off.
As for me? Well, I guess it's time I save up to finally purchase Studio One as I was a DAW that's going to carry on being supported. Frankly, there has to be some time when the servers get turned off, or authorisation on new machines is no longer possible. And as someone who's been very happy with how Sonar has been working for me, and getting used to the workflow, that genuinely makes me more than a little sad.