These guesses are really amusing: politics, religion, etc.
Steve doesn't vote. He wrote an article on why you should never have a religion.
But are those (religion and politics) the only things you can use to change the world on a massive scale?
Nope!
Look at what he's already done: entrepreneurship--that may be a hint, and can certainly be a big "change the world" tool.
Now think. What throughout society has brought us ahead by leaps and bounds? Invention.
His technology background kinda aligns with that too; as well as his entrepreneurship. Now, with Steve's business skills, and his utilization of blogging before it was big lead me to think he's inventing a new industry. And of course that industry would align with his values. The fact that it was a new industry would also mean there was no name for it.
If it *is* this, I'm really looking forward to it. With Steve's track-record, it will *definitely* be something to look into!