The chat feature has a lot of potential, but right now it is inferior to many other available options. Here are my suggestions on making it more customizeable and appealing.
1) Take a page from IRC's book and allow multiple chat rooms, private messaging and administrative control (which can be assigned based on guild rank).
2) Display ranks (with their color code) before names.
3) Add a time stamp, or an option for one.
4) Can Guests connect? If not, can they be allowed to through admin control options?
5) Allowing a widget version that players can see from other pages would be amazing, so they can chat while browsing the forums or wiki or whatever. Thinking like the calendar.
6) Chat shouldn't be lost so easily! Chat history should remain until the players close all the guildlaunch windows or intentionally refresh the chat page.
7) Chatters should have basic formatting options for their chat, such as colors or bold/italics/underline stuff.
This is not currently planned to be included in a development cycle, but we may revisit it at a later date.
I am in huge support for #6. I hate losing the chat when i leave that page. Its would be grossly beneficial to make this happen :)