Americans have been buying a Mustang expecting to receive an Audi for years now. The S550 is Fords response to this customer expectation. They also want to sell the car in Europe where it will damn well be compared to Audi and BMW.
I know that sounds wack, but truth be told; us, our forum, our hangout buddies, and our track buddies all live in an echo chamber. The loudmouths in the forums and on facebook often don't reflect whats happening at the point of sale.
Also I have been saying since day 1 of the S550 that they should have made a Lincoln version and put all the sound deadening and luxo weight stuff in that. They could even put the EB 3.5 in it to begin warming up buyers to the eventual demise of the middle class V8. People looking at a Lincoln are not married to the V8 like Mustang buyers are.