This story is is spot on: although network vendors make noises about reducing power consumption, in reality the nature of both their products and their locations in the datacentre mean that existing switches and routers aren't going to be thrown out in a hurry.
So there's not a lot of pressure on vendors to make their kit more energy-efficient.
And while I'm here, it should be noted that centralising everything - desktops etc - doesn't always make things more efficient. Not only is there a cost in money and energy associated with moving hardware and processes into the centre, it doesn't follow that the natural assumption that desktops will be replaced by thin clients and fat servers holds true.
In practice, they're far more likely to end up with laptops, which aren't thin from an energy consumption standpoint. And then, because the laptops will be either on standby or away from the office fir some of the time, you'll need to run up the aircon because your office space isn't being heated by a couple of hundred watts per desktop.
Free lunch? Don't think so.