I switched from Windows to Mac about a year ago. Before doing so, I spent months (okay, maybe even a couple of years) agonizing about whether it would be a good idea. Could I still _______? How would I _______? What if _______? What about _______? And even if I could do all of those things on a Mac, how long would it take me to figure it out? And even then, would I like it enough for the change to be worth it?
Well, within a couple of weeks after switching, I had only 2 questions: Why did I wait so long? And why do people still use Windows? I think the answer to both of these questions is that years of Windows use has conditioned us to expect everything to be insanely difficult. So the idea of switching to an entirely different platform seems like asking for serious trouble. But quite the opposite is true. Everything is easy, and everything works.
Now, having said that, Macs are not all things to all people. (Not yet, anyway.) There are some limitations. So you need to make sure that whatever you need to run can run on a Mac. In my case, the only app I used that doesn't have a Mac version is Sony's AcidPro for creating and mixing music. It turns out that GarageBand (which comes free on Macs) is a far better application. But my old Acid files are not (as far as I can tell) convertible. So it really depends on exactly what you want to do.
If you're near an Apple retail store, go in and try them out. Ask a lot of questions (they're used to it). Apple's discussion boards are also a good source for information.
"We're kind of on the level of crossword puzzle writers... And no one ever goes to them and gives them an award." ~Joe Strummer sscce.org