I think that an IRC client in the launcher would be a really neat idea. Both IDE and Doomseeker have one, but I think that making IRC a little more 'front and center' than either of those options would be a good idea, in order to make finding games with players easier. It's been done before; Doom Connecter had chat in the bottom pane of the server browser (not IRC).
As well as Doomwire:
And of course DWANGO itself:
One downside is that autojoining an IRC channel exposes your IP address to everyone in the channel unless you cloak yourself. Unfortunately, Quakenet does not allow ordinary users to cloak themselves unless they're registered and set themselves +x before joining. And as we well know, other networks are usually not as hospitable to gamers and clan scenes as Quakenet, and running an Odamex-specific IRC network would be overkill.
EDIT: A quick mockup