We are thinking as enthusiasts and not as company men trying to make a profit. The current Z4 is probably the sportiest car that 90% of the owners have ever driven. So, while I applaud the tone of this article, I think its unlikely that the next z4 will be that much different than the current offering. I think BMW has enough room in their lineup to make the m-sport and M models the ultra sporty models.
disclaimer: this purely comes from the bean counting, devils advocate portion of my brain. The real me wants real sports cars.