It slipped by unnoticed at the time, but John Howard mentioned "Darfur" by name for, I believe, the first time, in his Christmas message to the nation on December 24, 2006.

Even if it was as part of one sentence which looks like it was inserted into the speech almost as an afterthought:

It's also a time to remember some of the tragic trouble spots of the world; areas like Darfur in Africa and the troubled Middle East.

The complete text can be found on the Prime Ministerial website.