A few things I noted were:
The "social cost" of energy use
This referring to the social problems such as health-related problems, resource management and global warming etc. that come about from a unregulated, inefficient energy consumption. Randy Komisav talked about how the social cost of energy use is not refelected in the market economy, and how carbon credits are a way of adding in this cost, as carbon can be a proxy for these social costs.
New ideas about energy use
Lon Bell talked about changing the paradigm on how we heat up an electric car when there is no waste heat generated from combustion. Using in-seat thermoelectrics instead of the tradition air flow heating is the kind of paradigm shift that will be necessary when using new technologies.
Increasing efficiency vs. New more efficient technology
Many presentations discussed either increasing the energy efficiency of a current technology or developing a more energy efficient technology. All agreed, however, that both are necessary to for sustainable energy use.