Not long after releasing the second beta of iOS 7 yesterday, Apple also released the second OS X Mavericks developer preview along with Xcode 5 beta 2. If you want to download either update, simply open up the Mac App Store and the new versions should show up in the updates section.
As expected, there are some issues with the latest preview version. Bugs include display errors within Safari and iCloud Keychain.
Download the update and let us know what new features you spot, and report any bugs using the comments.