Concurrency concepts now, more than ever before

Multi-core microprocessors, hyperthreading and other technologies surely on the way to the target computers for your software application will need from you to master concurrency concepts more that ever before, here is in essence why:

"Chip designers are under so much pressure to deliver ever-faster CPUs that they’ll risk changing the meaning of your program, and possibly break it, in order to make it run faster"

The Free Lunch Is Over: A Fundamental Turn Toward Concurrency in Software by Herb Sutter