> At this point in time, sequential programs started getting slower, year on year, and parallel programs started getting faster.

The first part of this statement is plain wrong. Single thread performance has improved a lot due to better CPU architecture. Look at http://www.cpubenchmark.net/singleThread.html and compare CPUs with the same clock rate, where a 2.5 GHz. An April 2012 Intel Core i7-3770T scores 1971 points while a July 2008 Intel Core2 Duo T9400 scores 1005 points. This is almost double the score in less than four years. Of course, one factor is the larger cache that the quad core has, but this refutes Armstrong's point that the multicore age is bad for single thread performance even more.

For exposure to a more balanced point of view, I would highly recommend Martin Thompson's blog mechanical-sympathy.blogspot.com. It is a good a starting point on how far single threaded programs can be pushed and where multi-threading can even be detrimental.

Also, I think that fault tolerance is where Erlang really shines. More than a decade after OTP, projects like Akka and Hysterix are finally venturing in the right direction.