My friend says his VW TDI gets 55 miles per gallon. He has a 2 hour commute from time to time.
The new Passat Turbo-Diesel Wagon (available here in the US) easily gets 50-55mpg on the highway. Don't take it over 62-65mpg though, or the mileage drops significantly. (Drove one, LOVED it. Just wish I could find a way to give up the safety and comfort of my gas guzzling SUV to own one.)