It shouldn't be too hard to write an IRC server that is just a proxy and protocol translator to a real time microblog system, such as Twitter or Status.net or XMPP XEP-0277.
Using an IRC client, you would connect to this special IRC server, and login with your Twitter credentials, and be immediately joined to a special chat room. Every person who you are following or who are following you would appear to be in that room. The people you are following would have a +v flag. If someone you follow makes a public tweet, it appears as a message to that room. If you IRC private message someone, it is translated into a Twitter direct message. If someone Twitter direct messages you, it gets translated into an IRC private message to you.
If you ask for IRC info on someone, it will be taken from the Twitter user info.
If you IRC join a room named #foobar, you will join that room, but will not be voiced. That room will receive the Twitter realtime search results for the word "foobar" and for the hashtag "#foobar".
I'm not quite sure how to translate into the IRC-verse @ matches on your username. Probably also some sort of direct message.