Inflection point: Build for Higher Density or Plan for Efficient IT?

Over the last decade, the focus of the Data Center Industry has been to plan & renovate feverishly to support higher densities. Not too much of a surprise because there was actually an uptick in the scale of Morse's Law over the last decade as processing power, processing density & power consumption per rack unit all had risen faster than the industry had ever experienced.

Over the last few years the server manufacturers started to pay attention to power consumption as many of their clients couldn't deploy the new technology or had to wait until renovations or new facilities became available to upgrade to the newer servers that consumed more power in a smaller footprint. You are starting to see some products on the market that reverse the decade long trend & use less power. From innovations in operating systems that fine tune power usage as shown in this recent article by IBM:
http://www.ibm.com/developerworks/linux/library/l-cpufreq-1/

To Intel with its new Xeon 5500 series processors that is delivering up to 2.25x better performance and up to 3.5x improved system bandwidth are delivered in the same power envelope compared to Intel®Xeon®processor 5400. This processor also uses up to 50% lower idle power consumption during low utilization periods.
http://ipip.intel.com/go/wp-content/uploads/2009/05/intel_server_roadmap_050609.pdf

What is this forward thinking leading to? I believe we are going to cross the inflection point in the next couple of years where the high density environments we have or are constructing will outpace the power consumption demand of the new processors & servers we will need to deploy. It is difficult to say exactly when the big power saving breakthrough will happen at the chip level, but I think we all know it will happen. You don't want to be the last guy who built a MW facility @ 300 watts per square foot that now only needs 500KW & 150 watts per square floor. We often consider modular solutions that can scale up our density & capacity, but keep in mind that someday soon we may need to consume less power & cooling so we should make sure that our design is efficient at 50% or 30% of our design as well. Not just due to the inflection point where server power consumption will drop below data center power demand that Julius Neudorfer describes in the below article, but because our business requirements can also change where we won't need as much processing power to run our business.
http://www.itbusinessedge.com/cm/community/features/guestopinions/blog/inflection-point-the-future-of-the-data-center/?cs=36115