There's one thing you can always bet on with the Apple rumor mill: if they put a new feature in one of their devices, it will kick off speculation about them putting it in all the rest. Case in point: the original iPhone's touchscreen technology was pretty amazing at the time (though we take it for granted now). No sooner had the iPhone been released when people started wondering when we would see touchscreen MacBooks and iMacs. Similarly, the iPhone 4's retina display sparked rumors that the iPad would be getting the same remarkable technology (which it finally did this year). When the iPhone 4S came out last year with Siri, many wondered whether the new iPad would be getting that, too.
Of course, the new iPad didn't get Siri. Instead all it got was Dictation, which allows users to speak instead of typing. It's a cool feature, but it's no Siri. What if, though, Dictation on the new iPad was just a test run, and Siri will be coming to the iPad with iOS 6? Citing "trusted sources," 9to5Mac is now claiming exactly that. It seems that Siri will do everything on the iPad that she does on the iPhone except make phone calls. They claim that you'll be able to control media playback, iMessage, Reminders, and even get weather reports (despite the iPad's lack of a native Weather app).
According to the source, Siri on the iPad won't take up the whole screen the way it does on the iPhone. It's activated in the same way - holding down the home button. The iPhone's animation that shows the display sliding up to reveal Siri is replaced by an animation of Siri sliding out from under the display. Once active, it shows up as a window on top of whatever is on your screen.
It's not clear whether Siri will be available for all models of iPad, but it seems likely that it will be limited to the new iPad only (though you can bet the jailbreak community will find a way around that). It's also not clear whether Siri's migration to the iPad will be announced at WWDC 2012 with iOS 6, or will be Tim Cook's "one more thing" at the iPhone unveiling, which is expected to happen in the fall.