Gary, I think that the luxury buyer has pretty much gone away, leaving only the value buyers behind.
By "luxury," I mean, intangible benefits. "Green" has become a word with nebulous meaning, but the real benefits that energy-efficient homes offer, for example, are certainly salable.
I think that during down markets, it's essential to market tangible benefits, and "green" homes certainly have them. But we need to explain those benefits, and not treat "green" as a status brand that people are just dying to flock to.