Registration should be Wiki-friendly
I'm an internet dinosaur and have been using IRC before it was Internet Relay Chat. So it was not a problem for me to sign up. However, I think that the idea of a Wiki is that people don't have to be so well connected to technology to contribute. The fact that one has to go onto a chat server and sign up for an account here is going to block out a lot of people from contributing, simply because they either don't know what IRC is, or won't take the time to go and find a free program (e.g., mIRC) and learn to configure it (it's not trivial!).
I nearly gave up myself, because the attitude seems obtuse towards the contributers. It's something to think about, since 99.9% of all wikis are much easier to contribute to. I understand blocking random access is needed, because of spammers and defacers, but I'm not sure if draconian measures (logging on to IRC to ask for an account) are worth it. Maybe you should consider the other methods (e.g., capchas, email confirmations, etc.) that are much more user-friendly.
Just a suggestion...