I was skeptical when the button text change was proposed but I must admit that I like it.
I could stare for half a minute at the Yes, No and Cancel buttons, trying to process what button I had to press when my mind was in a different zone. After getting out of my flow I realized I had to read the whole freakin message to be able to tell what Yes and No were supposed to mean.
Now it is a bit like Jeopardy. I read the answer and I know the question. That workflow is so much faster.