Hi Rachel.
I bought a mini a month ago, and recieved it last week (if you do order one, order the keyboard and computer separately it speeds things up). My first impressions were that the mini was small, and it is… its basically a laptop squeezed into a desktop machine.

OSX is easy to use, although im still a little befuddled with it all. I have always used Windows, and a little Linux, but I really did like TopStyle and Wise FTP, they’re great programmes, but im sure their are some great mac replacements. Transmit is supposed to be very very good.
One thing that is vastly different is the mouse reaction speed, but a quick visit to the Microsoft site to download drivers sorted it! 🙂

Its a great adventure, Im sure you could replace both machines. Let us know what you decide to do, and good luck! 🙂