Dubs, don't be upset when you return far less than 50MPG. You obviously didn't do enough research or create a poll thread asking if anyone believes a new TDI will get 50+ MPG. You won't even get 45MPG. I'd say you'll be doing pretty well if you break 40 MPG. I don't care if you have the DSG or the manual, it's going to be a stretch.
Make sure you exercise the car on high speed runs at least once every couple weeks or so. That particulate filter needs to get nice and hot in order to clear itself. Yes, it has an auto burn program, but it's not the same as running the car.
Skip the APR chip, go for the Malone tune.
http://malonetuning.com/?page_id=564 APR has been tuning gassers for a long time with some success, but I wouldn't let them at a TDI.
Best of luck with the new Common Rail TDIs. I much prefer the older ones for simplicity and reliability.
My attempt to keep this a little more on topic... No picture, but I just purchased 14.5 gallons of biodiesel for the 600 miles I traveled. Just about 42MPG, but I have larger injector nozzles, a chip tune, a heavy right foot, and a short 6 mile commute.
BTW, summer time prices for diesel fuel are now in play. Prices for diesel fuel are currently below regular gasoline. I'd say the average diesel fuel costs over a year is in line with midgrade gasoline.