Pontious,
The 767 is the best tanker because it matches the USAF size/weight requirements.
The A330 is 50% heavier than the 767 and would be a replacement for the KC10.
The USAF has never had the intention to replace the KC135 by a KC10-sized jet, and Airbus rethoric won't change that.
If the USAF wanted to get an A330 sized jet, they would probably investigate converted MD11 tankers as a cheaper alternative.
BTW, it's no secret that the 767 is a more fuel efficient aircraft than the A330.