Savoia,
The fact of the matter is .... why should IB be wasting their time reinventing the wheel when it comes to chat, when they should be focusing their efforts on improving the fundamental core of Prune'... the forum, which is creaking at the seams (cf. multiple recent stability issues, all sorts of weird and wonderful database problems etc. etc.).
If you want to live chat, there are many better tools out there. So just PM the people you want to get to know better and then chat with them on Skype (or other tool of your choice).