Java ''programmers'' probably don''t waste time on IRC. I love IRC and its a great tool, but be careful not to get sucked into the endless babble of IRC. It can be very addictive and a HUGE waste of time.
Atleast i hang out on those mostly ircnet though. I consider IRC a must in java development, although there is a lot of crap talk and chitchat, but when you face a real problem you can mostly get help.