You might be right but hear my reasonings on why I feel you aren't.
1/ the A4 3.2v6FSi currently competes with the 330i, both roughly kick out the same power.
2/ the current S5 is only slightly quicker by the numbers than the 335i and in the UK at least the price difference between a 335iM/Sport and the S5 is only £3k. So one would expect the S4 to be similarly priced compared to the 335i saloon.
3/ the 335i is the top model prior to the M3, the same applies to the S4 which is also the top model prior to the RS4 when it finally arrives.
If Audi decided to drop this engine into the normal A4 then what would be the point of having the S4. Unless that is the point you are trying to make.