Not for introverts
Any expectations of a company that all their programmers should work in pairs does not take into account differences in temperament and personality type. A person who is an introvert, such as I am, would never be able to work that closely with another programmer. It is a certain recipe for stress disorders, and would put somebody in the hospital within weeks. (I once had a supervisor who caused me so much stress I ended up in the hospital. And I am a very easy-going guy).
On the other hand I could see it working for programmers who are gregarious, and who need discipline to focus on their work. But I don't understand why these people would ever become programmers in the first place...
