I know the admin had the idea not too long ago, but decided (at least for now) to not implement it.
In a forum like this one, I don't think having a live chat is a good idea.
Lots of people will ask questions, so you will have 5-6 questions, someone will answer to question #2, than someone else will answer to #4.
A third person will reply to an answer, and than no one will have no idea who's talking to who, and no one will have any answer.
Plus, with a chat like this, you can't really read back an old question.
When I have a question, I always take a look in old thread to see if someone didn't already posted it and had the answer.
So with a chat like this, the same question will always come out.
I know this is a great tool for quick easy and urgent questions... but everyone think their questions is always urgent and more important, so the forum will be empty and everything will go throw the chat.
Well, at least, this was my 2 cents
Maybe in the futur codecall will have a chat, only god (or the admin) know