A decent (randomized, has placebo control) recent article finding no transfer here (pdf). Not saying this is the final word on dual-n-back but enough for me to spend time elsewhere until more evidence comes in....
That was an interesting read, thanks. But I laughed out loud when they explained how they increased the IQ variance of their sample. The original study worked with students from the University of Bern, a group too homogeneous with respect to intelligence. To increase diversity, the replication works with students from Georgia Tech, Georgia State University, and Michigan State University. That is playing to the stereotypes.
Link.
Found here: http://www.reddit.com/r/cogsci/comments/wb44q/my_dual_nback_browsergame_is_ready_for/
From the author: