One of the biggest hurdles for allowing Windows software to be run under Mac was the difference in architecture that resulted in emulation software being required, which was slow. Now with the advent of being able to run Windows on a Mac, many people are doing them side by side. But what if you wanted to use OS X and run Windows software natively and at the same time? Still no easy feat but Parallels makes it possible. A virtualization suite, it supposedly runs Windows software nearly as fast on a Mac as it would on the PC. This could mean big things for the Mac:

"The trigger for our upgrade is the prospect that a significant number of Windows users will switch to a Mac once it's able to run Windows applications," Wolf wrote in a report. He cited a survey by his firm, which found that in the U.S., some 8 percent of home PC owners would switch to a Mac if it could run Windows. "An increase of this magnitude would almost triple Apple's share in the home market and increase it 75 percent worldwide," Wolf wrote.
That's an interesting point of view, and I wonder how many people really do feel that way. With a supposed difference of only 1 to 2% in performance for many programs, the ease of use in being able to run Windows apps may just convince many, and not just home users, to give it a go. Unlike a complete virtualization solution such as Vmware, Parallels is designed for programs only.