It makes sense that a $99 dollar net book from apple will happen with conditions placed upon it. For example, you have to sign a 3 year contract with AT&T for web use.
We're seeing similar deals with netbooks in Japan right now. In fact, I think I saw a nice acer netbook for $1 when signing a contract with a provider.
Dial-up providers did the same thing with computers in the US a decade back.