Safe Sleep Mode: http://docs.info.apple.com/article.html?artnum=302477 You're safe even if your computer loses power when it goes to sleep, all your data is written to your hard drive. So cool.
It's really not an argument for me anymore. If someone says the all-encompassing trolling statement, "Windows is way better than a Mac". I simply smile glibly and ignore them. They are dumb, and not worth my time. Even people who I knew were hardcore Windows guys made the switch. I will go into detail if someone is genuinely interested in the differences. But if it's someone who is trolling, I could care less what you think. Although I do remember a time after hearing it for the 50th time in a day (when I worked in the Apple Store), I put on my fast talking radio voice, and told the two nerds asking that you could develop for both Windows and the Mac all on one machine, and could even boot Linux on it now with the new Intel chip. It may have fell on deaf ears, but they left quickly, all the same. :)
In the past few months I've had my new Black Macbook (Intel Core Duo version), I am that more assured that Mac OS X will be the operating system of choice for everyone. I know in the geek realm that you are in a minority if you're using Windows nowadays. All the cool kids are either using a Mac or their favorite distro of Linux.
I do run a emulated version of Windows on my Mac, in the off chance that there will be some amazing software that I have to run, that only runs on Windows. But that is becoming less and less of a reality.
Ironically I do have a Windows PC at work running Windows XP (ick). I find it distasteful. It's ironic that I work for KW Media Group, Inc., a company run by Scott Kelby who's a huge Mac fan, and yet I have a Windows PC put in front of me? As a revolt I use my Macbook almost exclusively at work (with the exception of email using Outlook, although I could change that if I wanted to).
Even with Leopard being pushed back (see Apple Statement on the page), I think that Apple's newest operating system will be an even more enticing reason to make the switch. I made the switch, and I'm all the more happy for it.