I just pushed the 3rd edition to the store. If you’ve already purchased a copy, the update should appear tomorrow or over the weekend. Check for available downloads. As always, if you find any mistakes or if I overlooked any content with the new updates, please do let me know!
From the release notes:
Massive revision for Xcode 7.3, Swift 2.2 changes. Highlights include new examples for Swift 2.2, new doc rendering styles (much prettier, but also much larger so the screenshots suffer from being able to present less material at once). Removed (most) coverage of the now deprecated value capture feature, added strike-through for one section just in case a replacement shows up, added notes in the section about arranging assistants. Added coverage of new build configuration tests, enhanced the playground rich text markup section, added info about literals and embedded videos. Chapter 7 lost content because of the introduction of live interaction. Sadly, live input also disabled things like drag-and-drop windows and pop-ups, so a lot of the cute utilities that playgrounds could do in Xcode 7.2 no longer work. Sandboxing means that many really useful OS X utilities (although not all) are now history.