With the forecast from Wintergreen Research of a green datacenter market of almost $70 billion dollars by 2016 it certainly seems that green datacenter products is the way to go, and must be a high priority for people making datacenter spending decisions for the next few years. But when I talk to people making those choices, the picture doesn't seem quite the same.
The people I talk with on a regular basis fall into two categories; those who are building new datacenters and those who are responsible for the equipment lifecycle and buying new hardware. The first group is very green-aware; they are constantly looking at the new technologies, designs, and implementation plans that will enable them to roll out the greenest datacenter possible within their business considerations.
These folks are willing to make design trade-offs, build in specific ways, look at location changes and alternative methods of doing just about anything, as long as it will reduce their energy requirements and allow them to drive their business. They are looking at "green" with what is basically a holistic approach and the understanding that building the most efficient system for their needs will also deliver a greener computing environment than they currently have.
The second group is making purchasing decisions right now, and for them, green is a checklist item; they are willing to buy green, but not at a premium, and expect their vendors to just deliver more energy efficient equipment to replace their older hardware. Even conversations I've had with datacenter facility providers follows this model; their customers may ask about the "greenness" of the colo facility they are considering, but it is almost always a checklist item and not a factor that drives the business decision.
By 2016 I would expect every offering in the datacenter to be green, especially compared to those offered in 2009, and that designing energy efficient data systems will be the norm, and not an add-on selling point.