bill - 4:02 am on Nov 15, 2012 (gmt 0)
Regular updates are fine, and Windows 8 does that by default on a regular basis. It looks daily for updates even though the default for Microsoft is to regularly post updates on Patch Tuesday, mostly in deference to the enterprise market where out of band updates require extra testing and possible disruption to their networks.
However, I'd argue that system updates are not necessarily the same as virus protection. Sure, they may patch some exploit holes in Linux, but what if it's a 3rd party software that's being exploited? Is there a built-in scan in all Linux distros that handle those sort of issues? What if grandma opens an e-mail attachment with a Linux capable virus? They do exist.