There will be an on-site IRC application within near future. Otherwise, those of you who want to use a separate client, you can use Mibbit or FreeNode Webchat within your browser, or external applications like XChat or mIRC.
The direct link (for freenode webchat) to the DiabloFans chat room can be found here.
The server information is as follows: chat.freenode.net:6667 #diablofans and #diablowiki.
So drop by and chat with fellow DiabloFans about... anything!