Until the BETA is over, no one knows what Apple is going to do with Siri. They have not confirmed that the 4S is the only device that will get it once they exit beta. It is more than likely it will officially show up on the iPhone 4 and the iPad 2... other devices aren't as sure-fire. Give them a few weeks/months to develop and test drivers for the other devices and scale up the back-end.
10/31/11 at 8:25am