
Back to the Future...
The idea that MapReduce might not be the be-all and end-all of parallel computing shouldn't be surprising. Consider the more "traditional" field of large-scale scientific computing (i.e. solving PDEs). MapReduce is absolutely NOT the fundamental way to get parallelism because the different parallel parts need to communicate on a fine-grained scale.
The surprise to me was that something as simple as MapReduce was able to solve AS MANY problems as it has.