Yeah, I'm posting also to help make a business case. Like a few posts I have seen, we are a small interactive agency where all our designers work on Mac, the vast majority of designers I know work on Mac, in fact I'm under the impression that most designers work on a mac.
Parallels and VM work in a pinch but are hard on system resources, require an extra steps when setting up and cost money. I don't think I can justify purchasing software that needs to run in a windows environment, there are too many roadblocks involved. No matter how good your software is, to demo it I would need to demo Parallels or VM as well. It seems unlikely your demo will ever even get installed.
Another argument for a mac version is the community. It's tight, and Mac users don't search out or attention to PC software, regardless if we can run it.