Okay, this will take way too many Tweets for me to write out properly, so I'll type it out here really quickly.
"IRC," like most other words, is both denotative and connotative. Internet Relay Chat, strictly speaking, is just a protocol, but it comes loaded with an expected methodology and culture.
Ideally, we should take advantage of the former to fix some of the problems with the latter.
##IRC is Modular
The crux of this is that IRC is modular in the sense that, as a protocol, it only requires a compliant client and server. Beyond that, there is no way that it has to be. We can layer client features, server features, and other features like bots on top of it.
But there's certainly a way that it is, which leads to some of the issues you mentioned in your tweets the other day. I believe we can break these into three general issues for newcomers: technological barrier to entry, social barriers to entry, and ingrained hostile behavior (active or passive).
##Technological barriers to entry
IRC clients are tricky to set up. There's no shortage of guides to get people started, but better UI/UX could resolve this problem easily. Friendlier setup interfaces are the obvious option, but other things like distributable configuration files/wizards for specific channels or servers might be a good option as well.
##Social barriers to entry
This includes problems such as lack of response, massive numbers of lurkers, and uncertainty re: etiquette. Guides have been created to introduce people, but we can build solutions on top of IRC, such as bots that introduce people and perhaps coordinate volunteer "hosts" that are on call to help newcomers.
##Ingrained hostile behavior
This one's harder because you're having to change a stubborn, existing culture. Still thinking on this one, but #nodejs' "Policy on Trolling" is a good start.
Thoughts?
(Other readers: suggestions or additions are welcome via comment or fork)
Social Barriers
Still crystallizing my thoughts on this one, mostly, but one of the problems is indeed the silence. Especially when you are vaguely aware that there are mute flags and the like. Is it really this quiet, or do I need to have some flag applied by an op or bot to be able to see what is happening?
But even if it isn't that, and it's just quiet, it is a far cry from the other group chats people are used to these days, like zone and guild channels in MMO-type games, for example. Dare I talk? Am I disrupting people who are working? Are they even there?!
This extends towards the ingrained hostile behaviour, by the way. The average IRC channel feels like a mostly-quiet version of the trade channel or equivalent in MMO-type games :-P