Actually, none of this is necessary. The drive toward higher density per rack is a problem. By doing that cooling problems are made worse. I was at an event on data centers at the University of Illinois at Urbana-Champagne and a speaker from Microsoft discussed their findings. For one thing, space is not an issue, except in Tokyo and Hong Kong. Thus, you are better spreading the system out a bit.
Another thing they should consider, since they are using their own software, is another processor architecture. There are many very effecient processors based on the ARM and POWER architectures that might run their code faster and use a lot less power.