Apple has released iOS 4.2 Golden Master (GM) build to its developers. GM release is typically the final development build before it reaches consumers.
iOS 4.2 brings iPad up to date with iOS 4 features such as multitasking, folders, unified inbox and Game Center. iOS 4.2 also adds new AirPrint (wireless printing) and AirPlay (wireless media streaming) features, and is the first version of iOS released simultaneously for iPad, iPhone and iPod touch.
The final release of iOS 4.2 is expected this month. Apple might surprised us with a quick release in this week or next. We can also expect iTunes 10.1 to be released before or at the same time as iOS 4.2, as iTunes 10.1 beta is made available to developers together with iOS 4.2 beta.