Is Siri really more than a little bit of sugarcoating on top of stuff others have been doing for years (Google, Wolfram Alpha)? I suspect it is doing ok for some tasks (calendar), but that is about it. For example on Android people have been calling contacts by saying their names for a quite a while already.
I've never been able to get squat out of Wolframe Alpha. Even on things that seem like it should be right up its alley ("compare health care costs in Texas to Wisconsin" -- "no data available" -- Oh really?)
I think it is an improvement in the way it is integrated into the phone, but not in AI capability.