Is Energy Efficiency and Green the future

I've been following the "Green" concept for many years now and it appears that it is becoming more clearly defined as to what Green is, what it includes, and what it means when you are thinking of building a new home. The marketplace is changing. Will the change be irreversible? Have frugality and living within one's means become more important than building a McMansion. Are homebuyers looking for smaller, more practical, manageable, affordable and sustainable homes?--homes that will have a lifetime of energy cost savings. Has the move to Green-Energy Efficient thinking been bolstered by the rising cost of energy and a concern over global climate change? Or, will new home buyers sacrifice everything for excessive square footage?