I think IRC detracts from the purpose of a forum tbh.

Here you can read or join a conversation long after it has started and topics discussed remain available for future members to learn from.

With IRC if you aren't there at the time then you miss it.

Only way it would work IMO is for a regular IRC chat date/time where everyone gets together and, well, chats. (or more likely slap each other with wet fish and show off their ascii skillz )