My biggest reason for never using Mac is because of AutoCAD. The last AutoCAD I bought was 2000 with Desktop 3. I still use it when old clients call on me. However, long ago when I saw the new emacs on TV and I wanted one badly I called Autodesk and they said they were currently working on AutoCAD for Mac. Obviously nearly 5 years later they have not released even a beta to their customers. I recently called them because I have a pending sale on my windows machine and even though there are about 4 other windows boxes at my disposal, nothing feels better than my machine. Autodesk takes the stand that they're working on it. I asked about the mac-intel deal, and they kindly said that just because there is an intel chip coming doesn't make it possible to run windows. I just hung up from there. 😉
So no as everyone has said there isn't. But, I have yet to find a good replacement for it.