Following the release of OS X Mountain Lion Developer Preview 4 last Monday, Apple has issued a software update for that release (via 9to5Mac). It’s unclear exactly what changes the update contains, and there are no release notes available for the update so far.
The update is available now through the Software Update feature in Mountain Lion (via the Mac App Store). Apple issues two similar updates to the third developer preview. The update “”is recommended for all users running OS X Mountain Lion Developer Preview 4.”
The update comes it at a hefty 1.08GB, so don’t plan on going anywhere for a while once you start the download!