Vmware and Parallels halve most of Macs Processing power, bootcamping is too bothersome and in the end your still using Windows. Crossover Mac, now this is a good alternative since it can run windows apps inside mac natively no emulator no instaling of windows, the problem is flexlm protection doesnt play well with Crossover , stripping flexlm protection from ArcGIS might be a good solution. still no joy from Mac ArcGIS IMHO