How was 2.8L V6 changed from Audi?

I understand the 2.8L V6 used in some late model Passats used to be an Audi A4 engine. What changes were made to the Audi engine to put it in the Passat? For example: did the Audi have the drive by wire throttle? Was the engine tuned in any way, such as increasing ompression ratio? And so on.

The A4 now has an optional 3.0L V6. How is that engine different from the Passat 2.8L other than the obvious larger displacement? Are the electronics any different?

Thanks.

By the way, I read that the new S4 with the 4.2L V8 is out. That must be a hell of an engine for that size of car!