I watched about a year ago as a lawyer was forced to switch his time and billing from a legacy DOS operation into Windows XP because staff could no longer print billing invoices. I may be an ‘early adopter’ for Mac in litigation use, but the extreme of hanging on to old technology out of laziness and fear seems much less appealing. However, for those who love legacy programs like that time and billing in DOS, you might want to read an article on ARS Technica detailing why Windows is slowly but surely dying. In nutshell:
Mac OS X draws “[c]onscientious developers, who care about making an application that looks good, works well, and exploits the capabilities of the OS… Windows  has never struck me as being like that. The third-party software ecosystem for Windows is … incredibly shoddy. Most Windows applications—from both major software companies and minor ones alike—are ugly, poorly-thought-out, clunky pieces of crap. While there are a few artisan developers for Windows, most Windows devs just don’t care.
So, it is probably correct to say that more and more will ‘switch’ to Mac. The availability of Parallels and VMWare to run your ‘legacy’ Windows apps while transitioning makes it just that much easier. More than anything, virtualization brought me to switch. While ‘playing’ with Mac OS X, I became less and less tolerant of the Windows environment to the point that, well, I rarely boot up WinXP except when needed to get at some bit of information.