Developers running the first iOS 6 beta received a push notification of the update at around 9:45 p.m. ET (pictured at right.)
MacRumors notes that iOS 6 beta 2 is labeled as build 10A5338d (Beta 1 was build 10A5316k.) Oh and the gears in the Settings icon spin in a spiffy new animation when you're downloading the new beta (video).
iOS 6 beta 2 weighs in at 299MB on the iPhone 4 and 497MB on the iPad 3 (below).
9to5Mac is tracking the new features in beta 2 (including a Shared Photo Streams toggle, new Twitter icon, new TweetSheet in Siri UI, Reading List syncing over 3G, Calendar item ending times in Notification Center, Guided Access mode and more). Feel free to post any that you find in the TalkBack.
Apple also released Xcode 4.5 Developer Preview 2 and Apple TV Software beta 2.