I’m not saying that you thought that the ActionScript used in Flash 10 was ActionScript 4. I’m not saying I thought it. But, maybe your mom got a little confused over it all and asked you about it and you weren’t quite sure what to say.
There’s been lots of talk about ActionScript 4, and lots of new ActionScript features being talked about in Flash 10, including pretty fundamental changes like typed arrays / vectors. So, it’s no wonder your mom was confused. Just to clear the air, I asked, and got an answer from Tinic Uro.
In summary, AS4 is not even really fully defined yet. It will be based on ECMAScript 4, which you probably know. And even that is still being worked on. You can track the progress of that at https://wiki.mozilla.org/Tamarin:Tracing. It’s too early to even attach release dates or products versions to whatever ActionScript 4 will be.