This theory has been around for as long as OS X, if not longer but lately it seems to be gaining some credibility. There was the Mac "virus" last year, though it actually managed to infect less than 50 Macs in the wild. There was the report of a "dramatic increase" in OS X malware recently. And just yesterday ZDNet posted an article on vulnerabilities found in three operating systems: Leopard, Windows Vista, and Windows XP. They said that Mac OS X had the most vulnerabilities of the three (though it is worth noting that they are "vulnerabilities," not actual exploits. Windows still reigns supreme on that front).
Could these analysts be right? Should we be worried about the continued security of our chosen platform? Should Apple start focusing on OS X's security rather than simply adding more features?
Only time will tell, but one thing is certain: it is a scary world out there.