I don't mean to criticize the blog post, since it's probably valuable to some people. But if you're sick of Skype for Linux and you realize that something like IRC would be good replacement, then what's the point of writing an IRC server in Haskell (except for fun/education/pleasure) when you could use existing software (open source or not) like Apache Wave, Mumble, one of the many XMPP servers, IRC servers etc.?
I know at least one organization that mainly used the group chat bit of Skype. In that case, one might think it possible to replace it with XMPP or IRC.