I imagine that the biggest hurdle is the difference in computer OS architecture and the audio systems between Windows and Mac OS X.
Mac OS X is a Unix system, with some custom UI and other stuff like audio bolted on by Apple (This is not intended to be a comprehensive statement. It's a deep subject. Any questions, just Google it).
Cakewalk and Sonar have always been very tightly integrated with Microsoft and the Windows audio system. That is one reason why it can perform very well on Windows. But they are having to start from scratch with the Apple stuff.
If the bakers are going to attempt this at all, the first alpha release needs to be 100% stable and high performance, even if it is lacking a few features. Otherwise the criticism will be deafening. I really don't envy the guys doing this, the pressure must be tremendous!