How is it an UI? I mean it is voice input. OK, that's an UI, but it is an UI that has been around for thousands of years. Non-Apple phones also had voice input for years. Now Siri adds some things it recognizes, like calendar dates. What is so revolutionary about it? Other vendors will also add more tasks to their voice recognition. Google is arguably in a better position to do so, because they have worked on the problem for years (not voice recognition, but what do users mean when they search for "x").
I never said revolutionary, you did. Had you asked, I would have probably characterized it as "evolutionary" more than anything - but most innovation is.
I disagree that this is imply "voice input". Siri takes a step beyond simple data input and manipulation and provides a new interface to several system functions and services in a cohesive and purposeful fashion.
If, as you contend, that Google is well positioned to respond to Siri, then they probably will - I'm not sure you actually read my original comment - I had pretty clearly indicated that both Microsoft and Google have assets that they can deploy in response to Siri.
