kern's complaints on chat users aside, I like the way that interface looks.
The themes demoed on the page are easier on the eyes.
Maybe it's the age of my eyes, but, the dark text on light background seems easier for me to read for a chat field.
The Sound support I'm not so keen on unless there's a way to kill audio.
However, it does seem a more robust chat client.
I like it.
The only people who look like they'd be locked out of the Flash 9 requirement are Free/PC-BSD users.
Solaris, OSX, Linux and Windows'll all meet it though.
Should be something to look at to proceed from only basic chat functionality.