After Michael mentioned Norman's (and Nielsen's) dislike for Apple's gestural interfaces in class, I received a daily e-mail from Putting People First that features an analysis of their team's testing results: http://www.jnd.org/dn.mss/gestural_interfaces_a_step_backwards_in_usability_6.html.
Scalability is another important ID factor that we've had trouble with in light of the mobile site. Many of our publication listings throughout the site feature a line for pub title, one for the author, and one for the magazine issue. Against the generally recommended 40px x 40px spacing for mobile links, there's barely 2px separating each line and thus it is extremely easy to click on the wrong part of the publication listing, even for those with smaller fingers (of course, this is more of a problem on Androids and iPhones).
What this, overall, points out is a disconnect that definitely exists in UX design for the mobile world -- a disconnect between the new "context" (gestural interfaces, for example) and desktop-safe design decisions. Although Norman and Nielsen talk more about the use of non-proven design techniques in their article, there is a whole other cans of worms that clearly exists re: the use of *proven* design techniques that can't be adapted to the lawless world of gestural interfaces and mobile devices.