I don t think BMW will offer the same output as in Europe for the US diesel models...
In Europe the 20d & 25d models (2L: 184 hp & 218 hp) are the best in their class and have a very strong demand (more than 50% of 5 series for example are sold with one of these engines!).
On another hand, being in US I wouldn't buy any of these engines in front of a 28i model
The situation is almost the same for the 3L diesel vs petrol, 35d will never be better in US than a 35i!
The markets (Europe vs US) are very different so some diesel models have no sense there!
Still curious to see different opinions with some solid arguments!