Hi,
Over the last days, I've been working on documenting most of the new features of 9.0 from a user point of view. So I've built an 'illustrated' changelog, trying to explain to users what is going to change for them with examples.
The thing is, for now it's in french (sorry about that :) )
Here's the link:
http://blog.postgresql.fr/index.php?post/2010/06/16/Présentation-de-la-version-9.0-de-PostgreSQL2
(you can feed it to google translator, I just tried it, it's almost understandable)
I'm willing to translate it in english, if it's worthwile (1 to 2 days of work).
So, please tell me :)