Indeed it is.
I really hope Cortex catches on with more folks. I've been working with it to build a sci-fi/fantasy campaign for about a week now and I'm super impressed.
This wasn't on my list of books to buy this year but it is now. Even if I might buy it just to support the "free pdf with dead tree book" model. I'll do it just to hopefully convince other publishers this is the right direction to go.