Skype has about 30 million active users (an estimate based on simultaneously logged in users; they like to brag about the 200 mil+ accounts people have but many of those accounts are never used). Iphone 4 has sold 3 mil in a month and will easily quadruple that amount; still in the year to come the number of ip4 owners will likely fall below Skype user numbers. All of the former will also have access to a cheap or free Skype application, should they choose to use it.

Now, if video chat was such a great feature (many believe it is not, and I have personally had a hard time making a case for it here on TMO), people would flock to Skype. Its connectivity options immensely surpass FaceTime at present and in the nearest future -- they are putting Skype everywhere but the kitchen sink now.

Having said that, I think that Skype will sooner or later succumb to an open standard. Could that standard be FaceTime? The real question here is, is FT an open standard? Jobs said "we are submitting it to the open standard bodies tomorrow", but it seems tomorrow never comes. Apple fanbois all believe it is already open, and point you to Jobs's presentation, but noone has seen the specs, noone can access an API or a source. More informed people argue that the earliest it would be open is end of 2011.

If FT really opens up, then it would be trivial for developers to write the application you want. It would also be highly profitable for Skype and the like to develop one-way connectivity for calling out to FT devices. That way they can keep their proprietary protocol and attract more users.

Let's wait and see. I am very curious what will happen.