Lately since I moved from IT, I've been on Windows as I do no longer need to do any direct development work or alike. Presently my main job is to research on mobile services and products, design and implement them (along with the technical teams, but no technical work on my side). More or less its project management kinda work, so Windows is the obvious choice plus its company policy that all be under the Windows domain and I should not be an exception.
After almost 4 months of Windows at work experience, here is what I have to say. Nothing like MS Word, Excel and Visio. I guess this is the reason why Microsoft is still making money. Its not the OS. Never try anything (software) you do not trust. Just keep the usual stuff in your machine. With Windows you should always know that you are on Windows and at any time, anything can go wrong. Save and backup work as often as you can. This has helped me to keep away from problems and get the job done.
Anyway being a unix guy still inside forced to use Windows. So some how, secretly I managed to get Cygwin installed on my machine. Having it installed makes you always feel at home, you have all the usual unix tools available on Windows. If you are a developer, I guess Cygwin is the ideal tool. Its a good experience now, Mac OS and Linux at home, and Windows at work. Each fits in where it should.