I like this adaption of the Lean Startup ideas for UX design with the pivot that you should start the process with learning before building. It’s a very typical dev temptation to code first and ask questions later. A temptation worth resisting unless you like to throw away code.
I also agree that paired design can increase the quality of design–I’d say also that unless the two designers are identical clones, it will allow each to focus more on their individual strengths which is another reason the quality of output should go up.
http://www.cooper.com/journal/2011/03/more_better_faster_ux_design.html

This Wired article about Halo3 is actually work-related for most of you. I promise. It’s interesting to see usability testing as the savior for bet-the-business initiatives and to see heat maps and other UX design techniques applied to such a visceral experience. (Plus those of you not in the beta test can learn about the new weapons and vehicles, which is less work related… )

More here: Halo 3: How Microsoft Labs Invented a New Science of Play