I was just thinking of how GZ is really just a bunch of conversations.
As many of you know like on Gmail iPhone and other systems you can have a general topic but create sub topics by replying directly to someones comment with a quote...
I think that GZ could get some edge if you implemented a more user friendly AJAX approach where the conversation was updated dynamically. Great example was when Mauricio spoke of something I had just mentioned earlier. I do note your on mobile. But as the way of the new internet technologies a smooth transition would be cool.
And sometimes less is more, by the way it can take a lot of scrolling to see what people are talking about. One idea could be limit the size of posts kinda like facebook does and have a "see more" link.
Actually a lot of our usability changes are coming from facebook. it is the most used site and has brilliant examples of what to do and what not to.
Just a few thoughts...