I think you may have missed one of the central point that Urs was trying to make:

"Software development costs often dominate a company’s overall technical expenses, so forcing programmers to parallelize more code can cost more than we’d save on the hardware side."

There could be savings to be had by having a very smart scheduler that knows all about what kind of workload a given piece of task is by analyzing the code and dispatching it correctly. As you mentioned, though, that's not an easy problem to solve, and will also be a part of the software development cost.

From the programmer's point of view, that'll be yet another variable out of their control that may break the computing abstraction that makes these massive parallel machines possible.