I think many of *LTD*'s posts are a little over the top, but my user experience supports that OS X is generally speaking, safe. Yes, trojans and vulnerabilities exist, and they always will. But they are not an "every day" problem.
Every day I log into my messenger app and get "messages" from people who have somehow become infected with an MSN virus. Apparently there are even Facebook viruses. The other day I gave my USB stick to someone to copy a presentation and it came back infected with a VB script virus. I get spam emails with suspicious attachments. I've even visited shadier parts of the internet where one click of a web link results in suspicious looking files being downloaded instantly. Or that classic, a "picture" of a Windows dialog admonishing people who don't know any better to "download this now!"
Right now OS X is immune to ALL of those things. That's not to say it'll never change. In the future, it might get worse. But this is, today, already an "every day" problem for Windows users.
As for the claim that Windows 7 is more secure than OS X -- good! I don't know why people get in a huff about that. This isn't a contest. Windows XP is not secure, Linux is secure, OS X is secure, and you claim Windows 7 is even more secure? That's great news! The more people running secure OS's, the sooner we'll be able to get rid of these problems.