The keyboard is an answer to a question from the 50′s: How do we communicate commands to a computer with only our hands?
Siri is an answer to a more general question: How do we communicate commands to a computer?
I didn’t even consider this implication of the Surface Announcement. Microsoft isn’t even par for the course when the “major selling point” is a keyboard. Apple’s major selling point on the other hand is a revolutionary user interface.