Apple has been developing FaceTime over the past several months and has included it on such devices like the iPhone. But it looks like the free ride for FaceTime is about to end as Apple has just listed it in the AppStore for 99 cents.
What is not clear is if Apple is going to stop including it with its new products and turn it into purchase only service. Meaning that if you want to use FaceTime, then you have to buy it on every device that you want to use it on.
The choice to charge for FaceTime does seem a bit odd considering you can get Skype to do the same thing for free and that software is available on all platforms. It could be possible that Apple is only selling it for their older hardware that did not ship with FaceTime and that it could be included on all new Apple products (that have a built in camera).
If you feel so inclined to purchase FaceTime you can purchase it now or wait to see if Apple makes an official announcement about the product. Only time will tell to see if this service actually takes off but charging a small premium to use a service that has a free competitor that is widely used, may be a tough pill to swallow.