The latest developer build of Apple's upcoming OS X Mountain Lion dropped last week, and has shown off some iOS-like automatic app downloads to Mac App Store purchases.
Like on the iPhone and iPad, when you buy and install an app on one of your Macs, all of your other Macs logged into the same App Store account will automatically install the app too.
Unfortunately, the feature does not seem to be working completely. While the App Store will still offer to enable automatic downloads (as seen above), it does not actually install anything when you purchase apps from another computer.
This is something that just makes using a computer... easier. Not everyone lives on the bleeding edge of app updates, and not all apps auto-update. Hopefully we see something from Microsoft along these lines with Windows 8. But, then there's the case of what if an app was working perfectly before the update, and starts having issues after? Auto-updates are a double-edged sword.