Apple’s always been more about turning pirates into customers than dealing punishment that might ensnare innocent users (see Steve Jobs’ “Thoughts on Music” from 2007). That might explain why illegal copies of Apple programs are being upgraded to legit, App Store versions for users of OS X Mavericks.
The free upgrades apply to Apple’s iWork suite and Aperture for users of OS X Mavericks, the latest version of Apple’s Mac operating system. When upgrading to Mavericks, users of these programs are getting upgrades of the latest versions straight from the Mac App store, even if they had a trial version or an illegally-purchased copy.
Rather than maintain separate updates for these in addition to the Mac App Store versions of each app, Apple has decided to eliminate their legacy software update system for apps entirely. Instead, when Mavericks discovers legacy apps installed on your Mac, it provisions them as a Mac App Store purchase using your Apple ID. It saves us a lot of time, effort, and bandwidth.
It’s a nice thing for Apple to do. But it also helps hook users back to the App Store, and in a broader way keeps all users up to date on the Apple ecosystem. That’s precisely what Apple is trying to accomplish with all its new free software for Mac and iOS users as well.