following an increasingly limited use of Calamus SL on my Powermac G5 (no printing), I now use Calamus under VMWare Fusion and (still) XP. And I'm very happy with it. It's fast, and I can do anything I used to do with it in long past times. I've been using it for 2 months now, on a daily basis. I use Windows for Windows-specific tasks like the occasional Publisher and Word-documents, and for printing to printers that are really not supported on a Mac. And Calamus SL! I still find Calamus one of the most reliable programs, e.g. to generate PDF's. Colors, fonts, no problem at all. (of course, mind the masks and arrowheads of the lines, but you will get used to that).
So, again, for OSX 10.7 and 10.8 users: no need to despair. I'm very happy with this configuration.