Hybrid airships are not quite blimps. They require both vertical thrusters and forward movement to stay aloft, although they use lighter-than-air gas as well, so that they can remain aloft (while using less fuel) for longer. These military ships are due to be in place by the end of 2011.
Are these ships particularly green? Well, they do require less fuel to stay aloft than standard planes. But over the past few years there have been a few people looking anew at possible uses of airships and blimps in general, but this is the first major purchase that I've encountered. Here's hoping that it marks the beginnings of commercial airship manufacture. Airships use less fuel than planes, and could theoretically carry greater loads of freight.