Wow, that's a new one on me. I know that the Phaetons sold in Europe have a flexible service interval (rather than scheduled service), but even then, 2,000 miles is a bit early for anything.
Does it display any other messages explaining what it wants serviced? For example, references to suspension, emissions, ABS, etc? Do any annunciator lights on the face of the speedometer or tachometer (that are not green in colour) remain on after you start the car?
I think the only way to find out what the car is complaining about is to take it to a VW dealer and have them do a complete self-diagnostic scan, using the VAS 5051 or 5052 scan tool. It takes about 30 minutes (gross time, including bringing the car inside, etc.) to do this.
Here are some related threads that might be of interest:
Example of a 'Service Due' Message