According to a report from BGR, there is another cool feature that could be coming with iOS 6 this fall. Supposedly, Siri for the iPad will accompany the release of iOS 6 when Apple launches it later this year. Here's a quote with some details,

Siri for iPad will bring all of the features found on the iPhone 4S, except the phone-related commands for obvious reasons, to Apple’s tablet. Even though tablets tend to be positioned further away from a user’s mouth, Siri on the iPad is said to have “similar accuracy to the iPhone 4S.” Unlike the iPhone version, however, Siri for iPad will not be a full screen experience due to the tablet’s larger 9.7-inch display. The iPad version will instead open in a small window on top of whichever program the user has open.

Source: BGR