Apple released the "Golden Master" of OS X 10.8 Mountain Lion to developers yesterday which means that a full-scale public release is imminent barring any blocker bugs. According to MacRumors the build is labeled 12A269 and is being released as a 4.34GB download via the Mac App Store (the last developer update was build 12A256).
Mountain Lion made its public debut in February 2012 with a feature list that included iCloud integration, Messages, Reminders, Notes, Notification Center, Game Center, Messages, Calendar and Contacts. During WWDC 2012 Apple previewed several new Mountain Lion features including Dictation, iCloud Tabs, and Power Nap.
Mountain Lion will ship with 200+ new features in July for $19.99 and CNet's Topher Kessler's How to prepare your Mac for Mountain Lion is required reading if you're planning to make the leap to Apple's latest cat later this month.
And of you aren't a huge reader, this handy video covers 30 Mountain Lion features in two minutes: