From what has been drifting around on the grapevine here it appears we may have to set up our own datacentres, so this is defintely something that will go into the mix - I think it's not just essential from an environmental perspective, done well it also saves resources so we can defend that to the bookkeepers too.
As far as I can tell it'll be a lot of IBM Power gear due to virtualisation (at least it's all Unix), no idea what they do regarding sustainability. I do know they come out well regarding reliability, and given the scalability of the gear I don't see us replacing that often either (also helpful in this respect) but these things need power and cooling too. I suspect someone will drop networking of all of that in my lap, so I'm going to have to dig out some specialists soon.
Oh well, I suspect it'll take at least a month for mangelement to make up its mind one way or the other anyway.