James Leftwich has made his IA Summit presentation, The IA of Things: Twenty Years Of Lessons Learned, available online. The lessons he's learned are ones all interface designers should take to heart:
Symbols have the power to communicate concepts.
Designing across boundaries requires a very broad education and benefits from generalist experience.
The deepest, most impacting user experience design involves designing the physical controls, visual interface, and overall interactional architecture together, as a tightly integrated whole system.
The best design education is hands-on experience in all the various aspects of development and working alongside older, more experienced and mentoring designers.
The disappointing fact that the majority of design is not in groundbreaking innovation, but in variations on something successful.
It is worth taking measured design risks and pushing beyond normal development practices in order to achieve new levels of integration and usability.
Significant hardware and software constraints are not insurmountable barriers to successful usability.
It is very definitely possible to perceive and extrapolate user needs and develop successful interfaces without extensive user research, if one is adept at understanding generalized patterns.
The most powerful design solutions do not always involve abandoning current methods and embodiments.
Good interaction design is a discoverable quality, unlike product aesthetics and styling which are instantly visually evident.
It's valuable to reinforce informational and control interrelationships visually and interactionally beyond simple functional requirements.
A smart, holistic user interface strategy can solve problems beyond the immediate user experience.
It's possible to achieve great success by tightly integrating industrial design, interaction design, information architecture, and software design in a holistic, singular design effort.