there is an irc channel on freenode named #s4-project
Some connection instructions with Adium, a mac client (there are many other
alternatives of course):
Add account:
server: irc.freenode.net
nickname: yours
then go to File -> Join Group Chat
enter channel: #s4-project
you are in!
in order to automatically connect in Adium :
--> just use the contextual menu on the channel tab and do "bookmark"