Greg,
I don't have one... not yet, at least, but I know several people who do. They all just LOVE the thing. Incidentally, I work in an IT department, and almost all our managers have Macs at home, or on their desk next to their company-issued PC.
You have to download Bootcamp from Apple to be able to run Windows on it. It's a free download. You can also get Parallels, an application that allows you to run Window (or any other OS, for that matter) on your Mac. Parallels is better, but it is not free. The question is... why do you want to do that?? You can get Mac's version of Office and Outlook (called Entourage). Anything you do on your Mac (Word docs, powerpoint presentations, excel spreadsheets, and so on) is compatible with Windows.
Read the tech sheets on Apple's website for weight. I know they're light, though.
I will get one soon, and you should too. Great machine.
Juan