iOS 4.2 was announced in Apple's 2010 special musical event, Apple started rolling out iOS 4.2 betas starting from September 15th then followed by beta 2 and beta 3 and now we're testing the final gold master version. To sum up the new features, it brings Multitasking, folders, and unified inbox from iOS 4, also Game Center and TV show rentals from iOS 4.1, and adds in AirPlay video sharing and AirPrint wireless printing. Let's take a deep look at this features.

Hardware changes:
Apple has added a software orientation lock similar to that of the iPhone/iPod touch to iOS 4.2 to the iPad. This means that the orientation lock switch on the side of the iPad is now a mute switch, just like the iPhone. The only real difference between the iPad’s orientation lock widget and the iPhone’s is that it locks in both in landscape and portrait mode. But to be clear infront of you, there was an e-mail sent from Jobs to a reader over 9to5mac confirming that there's no hardware changes, we don't know what will happen in the public release.

AirPlay:
AirPlay is essentially an upgrade of apple’s AirTunes system, which used to let you stream music between iTunes on windows/Mac and Apple TV or Airport Express connected speakers. AirPlay steps it up and lets you steam media [video, pictures and music] from the iPhone, iPod touch, iPad and the 2010 Apple TV. It looks any app store app can stream as well as the built-in apps like iPod, video and photo if they so choose to do so.
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AirPrint:
AirPrint is another evolution of Apple's wireless printing service. You will be able to send pages to almost any printer on the same Wi-Fi network, or to certain printers directly.
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HomeScreen:
iPad has finally got iOS 4's HomeScreen with multitasking, folders and this wow background; Moreover, it got some new changes. In the upper right corner next to the battery percentage indicator there is not a small arrow pointing northeast, this icon indicates a location-based service is running, such as Wi-Fi mapping, or GPS; this feature is imported from iOS 4.

Multitasking:
That's the most important and big feature in iOS 4.2 for iPad, the arrival of real Multitasking to the iPad and guess what, it's different from iPhone's one. It's based on having your current screen slide to left, while the new one will slide around it horizontally to get on the front. Here's a video to see it in action:
AVRCP Audio / Video Remote Control:
Yes, you read it right, you can finally control, skip tracks, and everything you can ever dream with! Volume changes on the headset don’t show up on the iPhone’s volume slider, however, they do work in both iTunes store streaming and iPod apps.

Passcode Lock:
iOS 4.2 brings passcodes to the iPad. You can turn it on from the Settings app on your HomeScreen and yes it's a Vader-black keyboard
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Game Center:
iOS 4.2 makes Game Center possible on iPad which is already possible on iPhone and iPod touch running iOS 4.1. We already have seen some games being approved supporting iOS 4.2 for iPad.

Safari:
Yes, there's a bit difference in the web browser. iOS 4.2 gives the ability to search for a word in a web page, you can use the search field to type what you are looking for and find it. Besides, the previous + icon, for adding bookmarks and Web Clips is gone, replaced by the Action button found in other apps. Hitting the action button gives you all the same options as before, but now also includes AirPrint.

Mail:
iPad got a unified inbox just like iPhone has had since iOS 4.0. Unlike iPhone, the column view on the left of iPad lets you see your inbox choices on the left in landscape mode and in popover in portrait so it can be even faster to move around.

Youtube:
Youtube has got a major features in this iOS. You could give a YouTube video the old thumbs up or thumbs down right on your iPad. And yes, AirPlay is back to Youtube since it was removed in beta 3 but it's now there in the gold master release.

Notes:
You can -- finally -- change fonts in Notes. You can now jump into Settings and switch it to Chalkboard, and Helvetica, used by the rest of the interface.
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Restrictions:
This one is good for parents as it gives parents as much control as they possibly can with iOS 4.2. You can now easily restrict almost any feature of iOS, whether it’s deactivating location or messing with the account settings.
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Jailbreak & Unlock:
This is not a feature, but I wanted to clear out what's going on with iOS 4.2 jailbreak. Currently, iOS 4.2 is jailbroken but unluckily Cydia is broken on iOS 4.2 and we've got some screenshots for the new Cydia. Once iOS 4.2 is released, Cydia will be updated and you will be able to jailbreak your device with one of the tools on the web.

For the unlock, Ultrasn0w should be updated two days at most after iOS 4.2 release to unlock baseband 05.14.02. Baseband 02.10.04 should take a bit longer. Anyway, we'll inform you as soon as possible.

Before you leave:
I'm done! We almost covered most of the important features found in the beta releases of iOS 4.2 but in case you know other new features, you can leave us a comment below. iOS 4.2 should be available sometime this week or next week, stay tuned for that too.

[Thanks for TiPb, MacStories, AppAdvice, 9to5mac ]
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