A few ideas...

[Tolerian28]

I already mentioned one in the Opinions thread since I didn't know this existed.
My ideas are mainly Player List oriented since it has rarely been changed since it has existed.
One that just came to mind would be a check box for allowing staff masses, so you could toggle them on or off since some staff love to mass and their rights for massing aren't only when their tag is on.
More accessibility for the player list, like from the keyboard possibly. I don't use a laptop but I am sure the people who do would appreciate it. I myself dislike clicking or highlighting everyone. Just a thought.
Maybe something to toggle so when you just want to chat, you can receive messages in a pop-up manner and disable them while actively playing.
GLOBAL GUILD MESSAGING! Basically, if you are on a guild tag, and others are too on a separate server, make it so everyone can communicate. I don't know how easy this is to integrate though, just a thought.

I lost my train of thought but I have more. I guess I will just edit the post if they come back to me.