Here's an article
in a pretty mainstream publication - the Economist - that explains why concurrency matters. I used to say "the future is concurrent" but that was then; this is now and it's the present that's concurrent. As the article says,
What was once an obscure academic problem—finding ways to make it easy to write
software that can take full advantage of the power of parallel processing—is
rapidly becoming a problem for the whole industry. Unless it is solved, notes
David Smith of Gartner, a market-research firm, there will be a growing divide
between computers’ theoretical and actual performance.
I'll have some more concurrency material over the next little while in this space. Things continue to change pretty rapidly. If you haven't been thinking about concurrency, now's a pretty good time to start.