Apple will make changes to the rotation lock switch on your iPad when iOS 4.2 firmware arrives on the device this November. The beta version of the new operating system was released to developers today, and the external switch next to the volume buttons has been reassigned as a mute button.
Rotation lock still exists as an option, of course. The controls are similar to iPhones running iOS 4 or later. Double-clicking the home button will bring up the multitasking bar, which shows running and recently used applications. Swiping all the way to the left shows a specific set of controls on the multitasking bar.
Pictured above from left to right is a brightness slider, iPod controls, an iPod app icon, and finally the rotation lock selector. When the padlock icon is visible rotation lock is enabled. A blank icon allows the accelerometer inside the iPad to determine its orientation and adjust the screen accordingly. The iPod controls will also control compatible audio apps such as Pandora, if the iPad works similarly to iPhones running iOS 4.
Interestingly, Apple initially released documentation about the iPad before the device shipped that showed a mute switch above the volume controls. This physical switch was later changed to an orientation lock switch. Some reports have speculated that Apple expected to have more iOS 4 features ready before the iPad launch.
Apple specifically forbids developers from reassigning the function of physical buttons in their software to avoid confusion. Photography apps on the iPhone, for example, have had to remove volume button shutter released from their software to be approved in the App Store.