The X5 has a diesel option. By all indications, the X3 and Q5 will be getting them and the reason cited is to conform to Obama administration regulations on all car manufacturers to attain higher MPG numbers. Nothing about torque.
Moving on, I notice in addition to the Q5, Audi has a "Sport Lifestyle" car called the Allroad with the ground clearance and muscular appearance of an SUV but cushy like a station wagon not unlike the Volvo and perhaps some other station wagon on steroids types of cars. Their are no diesel offerings but all the models are built around their 2.0 turbo (read fuel sipping) engine.