I've copied this from the TPS website regarding servicing of all DSG boxes.
Service intervals:
The table below gives an overview of these gearboxes and their service intervals:
Gearbox type Gears Service interval Fluid*
DQ200 0CW 7-speed No service interval G 055512A2
DQ250 0D9 6-speed 40,000 miles - Fluid and filter G 052182A2
DQ381 0GC 7-speed 80,000 miles - Fluid only G 055529A2
DQ400** 0DD 6-speed 40,000 miles - Fluid only G 052182A2
DQ500 0DL 7-speed 40,000 miles - Fluid only G 052182A2
DQ500 0BH 7-speed 40,000 miles - Fluid only G 052182A2
DL382 - 7-speed 40,000 miles - Fluid only G 055529A2
DL501 - 7-speed 40,000 miles - Fluid and filter G 052529A2
All of my DSG boxed cars have had a 40K mile interval (not years).
AFAIK all of the wet-clutch DSG boxes have a 40k interval (both 6 & 7 speed).