On Thursday, Apple released the iOS 4.3 beta SDK. As part of the changes to the software, Apple has added an option to set the iPad's side switch to either the mute switch Apple wanted or the orientation lock that users wanted.
It's true that the change Apple, made, requiring users to swipe the screen to the right and then select the screen orientation lock on the screen made the iPad consistent with the iPhone and iPod touch, but the iPad has less of a reason to have a quick way to mute than the other devices, especially the iPhone with its phone ringer.