In addition to OS X Mavericks (version 10.9), Apple today is also releasing iOS 7.0.3, the latest software update for its mobile operating system. What's notable among the tweaks—which includes iCloud keychain support and bug fixes—is the fact that it allows iPhone, iPod touch and iPad users to kill the zooming transition animations that some users considered nauseating.
Some users have already gotten the new version, but others report nothing so far, so the update appears to be rolling out in waves (at least over-the-air). Once you've updated to version 7.0.3, you can find the control in the Settings app. (General->Accessibility->Reduce Motion.)
Note: The existing Reduce Motion toggle will show no difference visually. However, once you've updated the software, turning on the toggle will effectively shut off the zoom-motion animations.
Edited for clarity.