I don't know much about the reputation thing as it is new and I am in chat for the most part instead of posting in the forums, but I'd be interested in seeing some chatrep applied...I think having rep enabled in the room could be both helpful and useful in more ways than one.
I'm also in favor of doing away with (some of) the other rooms. They only take up space and tend to confuse new folks who wander through the chat. Being able to block pm's would also be wonderful, as well as being able to copy/paste from the chat window.
The moderators do such a fantastic job and get little recognition for their hard work here. I'd like to remind everyone who may have issues that these folks moderate the rooms to the best of their very impressive ability out of the goodness of their hearts and try to keep it a positive environment for us all. While you needn't agree with mods and it is a free speech site, I'd encourage you to consider that berating or trashing folks really says more about you than it does about them.
Here's to everyone that makes chat the great little dig that it is!