I've heard a rumor that there will be a diesel option in late '06 or mid '07. Is there anything to substantiate this rumor? Supposedly near 30mpg is possible.

You guys are going to love your Q7s...my Touareg has absolutely lived up to expectations.

Fuel quality in the U.S has to improve first.
(Too much sulfur!).
But it will be available on the A6 and the Q7 for sure in about 2 years.

maybe even by year's end, when ULSD will be widely available, according to Filip Brabec, Audi product manager for North America.