As much as I'd like to see it for personal reasons, I don't think it'd be a wise decision. Considering that this is a niche market and that it's already very crowded, it wouldn't make much sense financially.
Every Mac comes with a DAW software (that's actually not the toy some people assume it is), and you can get Logic for $225. How do you compete with such a powerhouse at such a bargain price?
Big studio run Pro Tools no matter what. They won't switch to Sonar or anything else any time soon, so there's no point in seeking "credibility" there. Hollywood composers and the likes, all those folks with more or less fame attached to their name usually have a set up that allows them to pump out music w/o wasting time.
They are often quite reluctant to learn a new DAW, because, well, they're busy earning a life making music.
And why would they do otherwise? Logic, Digital Performer, Cubase already provide top notch solutions. Not only that, but these all have the one feature that Cakewalk couldn't care less for - proper notation.
Other than that, unless you're offering something different, such as Live! or Reason, you're fighting an uphill battle.
The only people I've seen who had interest for something like Sonar on Mac are ex-Sonar users now working on Mac. That's the only semi-serious potential market I see.
Think about it... MOTU, who's always been 100% Mac since over 30 years ago, with zero interest in PC finally made the move and came up with a PC version of Digital Performer last year. What this tells me is that the Mac market just wasn't enough anymore.
Cakewalk is doing the right thing. The rich and famous market presents virtually no opportunity for them.