Go Mac. I switched 2 years ago and love it.
I have the Microsoft suite for Mac for school, so I can do my papers, etc. anything you do in Office I can open, edit and send back to you. If there are programs that you have to use that Mac cannot run (like CAD), then I suggest using Parallels.
Stay away from the MACbook air. It's cool, but there is not a superdrive, and only one usb port. You can buy an external Superdrive but it runs off of USB.
Now Mac's cost more. A lot more. Last year when we bought a laptop for the church I counted 27 different companies that sold PC's. There is only one company that sells Mac. No competition means they can set the price wherever they want.
Built in ISight camera, built in bluetooth. Safari is a great web browser, and the ILife suite is unbelievable. IWork is great, Keynote is much better than PowerPoint, Pages is better than Publisher and Word, and Numbers puts Excel to shame.
The biggest problem they will have is that Leopard is more intuitive than Vista, or XP. All those Keyboard tricks are not needed in Leopard. They might have some trouble with a one button mouse, but you can buy a bluetooth two button mouse.
I hope this helps.