I started keeping Skype running after reading a TechCrunch piece explaining how screen sharing works over Skype. I needed exactly this functionality to support a few friends who are new to blogging. To be able to see what's on their screen instead of relying on their description makes a huge difference.
Using Skype makes me wonder what if they gone in the direction that Twitter did, making it possible for status messages to scroll by in a River of News. It's amazingly close to what I consider the ideal configuration. A centralized name service with peer-to-peer updates.
But Skype was embedded in a large company, and who knows what kinds of pressure they were under. It certainly wasn't being run in an entrepreneurial way. Which led me to wonder how different things would have been if Skype had an API. A simple one that allowed you to push a message to another Skype user, and be able to catch a message flowing into the Skype client. Could have been great.
It's a lot like rssCloud or what Dropbox is doing. Sooner or later there will be a unifying layer that handles all real-time traffic through an open API that doesn't rely on central servers any more than the Internet itself does. It's coming, you can feel it.
Update: Skype does have an API.