I bought an iMac a year ago, and still love using it. It's the first machine I've truly enjoyed using in more years than I care to remember. However, I did hang on to my Windows 7 laptop, probably because I was a little worried the Mac wouldn't do everything I needed.
Suffice to say that this week I bought myself a MacBook Air 13" and have sold on the Windows laptop. I'm now entirely Mac based and finding things so much easier. The simple fact that without hours of configuration, I can access my files on the iMac from my Air in the next room.. That's what computing was supposed to be about years ago.. Now it's finally here for me!
One further development.. I went out yesterday and bought my wife the 11" Air too! The only regret is that apparently she needs to buy her own copies of iWork unless she registers the machine in my name, neither of those solutions are ideal, but then I guess we can't have everything.
Whatever you decide, enjoy your new Mac experience.