Warning - this post involves a lot of gushing.
My company's first Cocoon based web application is live in production now =) It is an internal application so I cannot point you to it though =/
I don't think I can stress enough how much anyone out there who hasn't taken the time to look at Cocoon for their Java web apps needs to, RIGHT NOW. Once you grok how it works (and yes, it is a different paradigm than almost anything else in common use) productivity goes up by leaps and bounds over action-oriented frameworks. I am a convert.