Last month’s cluster of “Mac Defender” malware flareups felt like a flashback to 2001, with the role of Microsoft being played by Apple. The malware, which took advantage of poisoned Google images search results to trick users into installing fake anti-virus software, first appeared in variants that required an administrator password for installation.

Soon, though, later versions appeared that didn’t require a password for installation, provided that the user being fooled was running with administrator rights–the default for the first user account set up on a Mac.

While much is made of how the root account is disabled by default on OS X, administrator accounts on today’s OS X are less tightly controlled than administrator accounts on Windows 7–a result of the decade that Microsoft spent dealing with security issues, delaying its efforts building a strong successor to XP.

However, the big difference between Apple 2011 and Microsoft 2001 is that the way forward for Apple needn’t involve bolting on potentially confusing new security layers to its desktop OS. Instead, Apple has a second, and significantly more secure platform to offer its users: iOS.

Where OS X relies on a fairly standard Unix permissions structure based on a admin/user divide that home and corporate users alike find challenging or annoying to abide by, iOS provides a mix of application control, isolation, and resource constraint that’s proving both palatable and secure.

Rather than figure out a way to enable every user to fiddle with their machines like a hobbyist while preserving the security and stability of a well-managed desktop, Apple’s managed to convince its mobile users that less can be more. Smartphones, which we got to know as a constrained and underperforming platform for computing, offered an apt proving ground for these ideas.

A retirement party for OS X may still be a little way off, but given the growth of iOS, and the iOS-ward course that Apple has charted for Lion, there’s no way that Apple’s primary OS of 2021 will as closely resemble OS X as Windows 7 does XP.