I think that is one of the big tech developments of the last 3 years... Microsoft's iron grip has really been broken. No longer running Windows is a requirement to get work done. It was really helped along by MS's botching of the Win 8 release, but I believe Apple's iPad was key. It broke the dam and Google Android helped flood the market.
Many of us learned a long time ago (or not that long ago) that you can live and work efficiently without Windows. the continuity between OSX and iOS truly enhances the usability 10 times. I already love that if I make a note in OSX's Note app, it shows up on my iPhone and iPad; if I add a contact on my iPhone, it is on my Mac; my photos are all in a common photo stream, there is a nice web-interface to access all of the iCloud features; heck I create Keynote presentations for class, but the classroom computers are windows-based. So I login to iCloud.com, and serve the presentation from the web.
There were only a few apps that I missed when I switched, but in the past three years, each of those are now OSX native. I do not run Parallels, or attempt to run windows in a bootcamp mode. It isn't needed. And tools like DevonThink Pro, and a word processor like Nisus Pro Writer (all the power, none of the bloat of Word), improve my efficiency. The only MS Office app I use regularly is Excel.