in looking to create a new communication mechanism on the Internet, the features of twitter and irc are compared.
defining features of irc are channel creation is open to anyone for any channel name. messages are delivered to each client using persistent TCP connections.
defining features of twitter are: each tweet is saved. a record of tweets is available on the web. each speaker has a small profile page including a home page link and profile photo. a list of friends is associated to each user.
irc has no friends list concept, it has channels. anyone in the same channel is there because of a common interest in the channel topic. there is no need for an explicit friends list. the user remembers the nicks of friends.
twitter has no channel concept, it has friends. if you are my friend, we are in the same channel. there is no way for 3 friends who have other friends to speak amongst themselves.
twitter is provided by a single service provider that has an API
irc is a standard protocol that can be implemented by anyone and anyone can run an irc server. servers can network together to allow users to join channels on remote servers.
when a message is given to a channel, it is distributed and then forgotten. the irc client will keep a backscroll for as long as you are in the channel. you cannot login and read what you have missed since your last login.
the new protocol, i imagine, would use regular URLs that are treated as openid identifiers and as a service discovery location. use xmpp or create an xmpp-like peer to peer RPC mechanism, with optional aggregation points (servers) and zeroconf discovery. use multicast to help with message delivery (ipv6 would help).
feature: Cafe Discovery. if your laptop is running the client, you will be detectable by others via zeroconf. great way to meet new p2p-twitter follower potentials. (note: come up with better name)