All Bush is doing by granting her this interview, is granting her credibility. He has always been gracious to his critics and opponents and will not get into the same gutter with her when she starts taking cheap shots and low blows.
Frankly, I think he should have come up with a "scheduling conflict" to avoid ever doing an interview with her.
You people are missing the point here, big time! Bush does the interview because he knows everyone is watching it to see how Katie handles herself. She either is gracious and respectable, or childish and arrogant, either way she'll make Bush look GOOD!