According to this study, it seems that habitable zones around other stars have either shrunk in size or have become even rarer (or both) than previously thought.
Interesting links.
Demonstrates how little we know about life-originating and life-sustaining environments. I have a feeling a lot more restrictive criteria will eventually be defined. The ecosystem of the Earth is so finely balanced one would have to think the chances of finding life anywhere "close" is pretty slim.
