John Battelle discusses the importance of Google Talk offering interoperability between AOL IM, MSN, and ICQ, among others.
I have had partial interoperability for a long time, using an IM client called Trillian from Cerulean Studios. Trillian offers the ability to run all the instant messaging services through one client, which is important because people tend to be in different networks (my kids in MSN, former colleagues in ICQ or IM, current colleagues mostly in IM.) What Google Talk would offer in addition, I assume, is the ability to have multi-party chats with people in all those other networks, thus obviating the demand side network externalities which work for whoever has the largest market share (in each sub-segment). Given the trouble that Trillian has had keeping up with changes in the IM services, I have a hard time seeing MS opening up MSN to Google, but if enough people sign up for it, things might work out.
Which goes to show that interoperability forces its way through once enough people start using a service that is offered by several companies. Funny that MS hasn’t offered an MSN client that can talk to anyone a long time ago…..
(Incidentally, my Google Talk handle is, I suppose, espenandersen@gmail.com)