Sustainability has long been considered a business goal for mitigating risk and focusing on compliance, but only including cursory tasks and projects that develop an overall sense that the company is a good corporate citizen. At 1E, we have long believed that implementing efficiency in technology should be a precept of any sustainability program. The triple bottom line of people, planet, profit can all benefit from IT Efficiency, and the rewards can be obtained much quicker than altering any other aspect of the business.
eWeek has an article that talks about how Gartner has also come to this conclusion and is prescribing that businesses include IT Efficiency in the sustainability plan.
Some significant quotes from the article:

Sustainability is no longer about risk mitigation, focused on compliance, reputation, philanthropy, the triple bottom line (people, planet, profit), and generally being seen as doing “good things”, Gartner’s analysts claimed. The issues are much closer to the daily running of the organisation: operational efficiency and business enablement.

Gartner predicts the position of sustainability will rapidly move up the company priority list by 2015.

Mingay believes that, in IT provision, energy-efficiency moves on their own cannot meet tomorrow’s challenges. The much bigger opportunity is applying IT to analyse, optimise, manage and otherwise improve the sustainability performance of the business itself.