Line-in accessories are now supported in the SDK. Applications will be able to receive audio input on all devices. You should use the kAudioSessionProperty_AudioInputAvailable to determine if audio input is available at any given time.

By default, third party applications now respect the ringer switch position. If you want to play audio even when the ringer switch is in the silent position, use AudioSession APIs and set an appropriate category.

kAudioSessionCategory_SoloAmbient is a new audio session category that respects the ringer switch like kAudioSessionCategory_Ambient. However, unlike kAudioSessionCategory_Ambient, which mixes in with songs, it interrupts all other audio playback, allowing the application to use the hardware audio codecs (MP3, AAC, Apple Lossless).

By default, audio will no longer play when the screen is locked. To play audio in this state, use the kAudioSessionCategory_MediaPlayback audio session category.

Audio silenced when the screen is locked will remain silent even after the phone is woken up. To play audio after the phone sleeps and wakes up, set up an audio session and, when you hear the interruption end, restart your audio.

AVAudioPlayer is a new audio object in AVFoundation for playing audio files that provides the following:

• Simple commands for play, stop, pause, setting time and volume.

• Will play any audio file recognized by AudioFile and AudioQueue (the objects used to implement this class).

• Provides a delegate to handle interruptions that form part of the services of AudioSession.

• User can enable metering and use the resulting values to present a visual display of the audio levels being played at any given time.

The user of the object still controls the overall behavior and interaction of the audio player through the audio session APIs and categories.

kAudioFormatProperty_FirstPlayableFormatFromList='fpfl' is a new property added to audio format. This property can be used to take a format list from one of these file formats and return from that list the first format in the list that can be played on any given device. This is based on the availability of decoders and other factors in the specification that may influence the ability of a given implementation to render the contents of a bitstream. If the format list from the audio file/stream has more than one entry in it, or the FirstPlayableFormat property is implemented, do the following:

• Pass that format list to this property to get back the index of the actual format you should use to create an audio queue.

• If the property is not implemented (earlier iOS for example) then just take the last item in the format list (this is the most compatible) to create an audio queue.

If a nil NIB name is passed to -initWithNibName:bundle: and -loadView is not overridden for the view controller subclass, the view controller will attempt to load a NIB with a name matching the view controller.

The UIInterfaceOrientation property in an application's Info.plist is now respected for view controller-based applications. To launch an application in landscape, set the UIInterfaceOrientation property in the property list and make sure the view controller returns YES for the desired orientation in -shouldAutorotateToInterfaceOrientation:.

When presenting or dismissing a view controller modally, the appear & disappear methods will be called exactly once for a modal present or dismiss, with the correct animation parameters.

Setting the first responder to a UITextField or UITextView in -viewWillAppear: is now supported. Doing this will animate the keyboard in to match a push, pop, modal present or modal dismiss.

iOS Simulator does not support network home directories.

The version of Foundation in the simulator platform includes functionality not included in iOS. To ensure functionality is not used that is not present on iPhone, check the documentation for availability information.

Toggling between 11AM and 12PM may result in the Date Picker showing 12AM rather than 12PM.

You have to specify the image extension to -imageNamed: to get results.

Including the degree character in a format string disables text updates to a UILabel object.

UILabel ignores its contentMode property.

After zooming, content inset is ignored and content is left in the wrong position.

UILineBreakModeTruncateHead and UILineBreakModeMiddleTruncation do not work properly for multiline text.

UITableView ignores separatorStyle and separatorColor.

UITextView objects embedded inside a UITableViewCell never receive touches.

It is very, very expensive to customize row heights (via tableView:heightForRowAtIndexPath:).

Unable to resize table wider than the screen.

UITextField cannot be made to resign first responder once offscreen.

Setting UITextView.editable to YES should not automatically show the keyboard.

-[UIToolbarController setSelectionIndex] doesn't work for members of the viewControllers array that are offscreen.

UITouch is not adjusted when a layer has a transform applied to it.

UITouch does not properly handle multiple taps from multiple fingers.

An application will not receive UITouchPhaseBegan if a swipe begins on or above the status bar.

Many UIKit controls cannot be resized properly if initialized with a CGRectZero frame.

animationDidEnd fires too soon and can cause animations to stutter if you do too much work in the callback.

If a view subclass implements -drawRect: then the background color for that view subclass cannot be animated.

UINavigationController won't resize content view automatically if barStyle is changed to/from UIBarStyleBlackTranslucent.

If a view is detached from a given UIViewController as a top-level nib object, but connected as an outlet, the view's origin is incorrectly moved upwards by approximately 24 pixels.

Links don't highlight when WebKit is single threaded.

You may only use .png files for application icons for the device.

The iOS SDK is designed for Intel-based Macs and is not supported on PPC-based Macs.

Xcode and the iOS SDK only work in 32-bit mode; 64-bit mode is not supported.

When running and debugging on a device, be sure to turn off Passcode lock.

FIXED: Using the Xcode menu Run > Start with Performance Tool > <instrument> does not work even though it is enabled. The application is not uploaded to the device. When the application is already present, Instruments targets the local machine and "Target failed to start" appears in the tracks.

Trying to debug two applications at the same time on the same device fails with a broken pipe error in the debugger console.

FIXED: Instruments will act unpredictably with multiple devices attached.