There's probably a lot of people already at the OSDev IRC channel.
I know that you just need to do something like install Pidgin, use the default FreeNode server, add an IRC user name, and enter the #osdev channel.
I made a video showing how to do that some time ago:
http://www.youtube.com/watch?v=dw9ya68HacIBut it seems that the newest users don't go to the IRC channel too often. Maybe that could speed up things in general more than just with the forum given that it's a chat and thus the fastest communication media.
I mainly wonder about the newest users, maybe most people come from IRC itself, but I think that making clear that an OSDev channel exists and that it would benefit the development environment to have everyone from the forum to IRC, is something that I had to do so they actually use it.