Porsche said on the IAA 2005 that they plan a Hybrid Porsche Cayenne.

Do not expect a Porsche Cayenne Hybrid SUV anytime soon at your personal Porsche dealer. Around 2010 it might be available.
The German Car makers are very late to the hybrid technology. Japanese car makers are miles ahead. VW announced together with their Audi and Porsche units hybrid technology push. Apparently Audi will already show a hybrid of the new Audi Q7 at the IAA, which should hit the roads in 2008.
I am all for alternative engine technologies. The car industry is way to focused on horse power. The current fuel prices help to drive the need for alternative energy. A hybrid Porsche was already news in October 2004. Forbes has small Porsche hybrid announcement from the IAA 2005 in English.

So far the announcements and new car introductions on the IAA 2005 (site) are not overwhelming. Let's see if there is still more to come.