I'm far too impatient as well, I suppose. It seems to me (from the armchair where I quarterback) that IM interoperability isn't happening not because companies prefer the advantages of their chosen protocol, but because they simply want to "be the platform." I can't imagine a better advantage than actually being able to talk with any of my friends on any other client.

If email hasn't proven a standard can be beneficial to everyone, I don't know what would.