The Instant Messaging standards proposal, based on SIP (Session Initiation Protocol) has just gone to IETF (Internet Engineering Task Force) last call, before being made a standard. You're probably not as excited about this as I am, but you might like to know.

What this means is that the same infrastructure that was designed for Internet phones and real-time conferencing, voice and video, will also likely be used for little ol' text messages. There is a drawback: the infrastructure for voice and video is difficult to put in place. The well-known port for SIP is 5060, and any protocol that doesn't use port 80 has trouble getting started because many firewalls block ports by default. On the other hand, there may eventually be an advantage to integrating these protocols because it should lead to better integration of presence information.

Presence information is pretty key to successful instant messaging. It's much easier to know when to pop off a quick text message if you know the person is tuned in. Right now presence information is rather unsophisticated: you can be online and active with your IM client, or away, idle, or completely offline. What this doesn't provide is any awareness of non-IM activity: whether you're on the phone, in a chat room, in a video conference, etc. Current IM clients don't show if you've just stepped out of the office, or if you've allowed your screen to go blank because you're reading a magazine. This is all information you might decide to feed into your presence information for those you allow to know your status, in order to help them decide how best to communicate with you. Integration with some of these other activities at a protocol level isn't necessary to integration in presence information, but I hope it helps.