Facetime made its grand debut as part of iOS4 (specifically on the iPhone 4 hardware). It expanded to a nice user base once the fourth generation of the iPod touch was released. In today's event, it was announced that in the first four months of Facetime's existence, said user base grew to 19 million people.
Now those 19 million people will be able to talk to all the customers of Apple Computer who actually purchased a computer! As of today, the beta for FaceTime will be available for computers as well.
Steve did a quick demonstration of FaceTime with Phil Schiller who was on his iPhone 4, and it looked pretty smooth. So far the only notable piece of the announcement is what was missing: A Windows client, or at least integration with an existing messaging application.
It is starting to look like iChat's days might be numbered, since we heard no mention of it and now the way forward appears to have a new icon.