It would make things a lot easier for clans who need an accurate player count. Even when counting a clanchat for players inside, it can be difficult as players come and leave constantly.
A simple overlay similar to osbuddy could display an accurate number in the top right of the clan chat. This would also help when recruiting for "x player" size raids
I would also like a player counter inside raids if possible, this could update when players dc/leave as well possibly? This would help teams know when everyone is inside, as well as knowing when people are leaching much easier (mass raids people just leave cc once inside and can hide within the raid)
A proper display of clan chat rankings would be nice, along with donor/ironman status would be nice. I often get asked questions by players about training method etc, and much of my feedback involves them being a donator - this update would allow me to know if they are or not.