Windows Switchers: There's a Mac app for that
Eight years ago when I switched from Windows to Mac there was a distinct shortage of good consumer apps for OS X. For a good two years I had to keep a PC handy for essential tasks that I couldn't easily complete on a Mac. That has all changed and there is hardly anything you cannot get for Mac. I know of one, though: A tax calculation program and that is the only reason I keep a Parallels Windows volume on one of my Macs. Admittedly, this is a very special area and shouldn't concern the majority of switchers.
Moving over from Windows to Mac is now a fairly painless procedure and the least pain comes in choosing alternative applications. The excellent Mactuts+ website takes you through all the apps you are likely to need and explains how they differ from their Windows versions. Read more here.