Publishers have realized that, unlike the previous time period, American teenagers are both smarter and require more topical material than they had been giving them before that. For one thing, they'll read thicker books. Besides, has anybody looked at the news or read the newspapers recently?
After I recovered from 'Lioness', I wanted to write something about animals because I really like mythical creatures, especially dragons. At 12, I was one of those semi-recluses who did better with animals than people. Out of that, came the character, Daine, who could communicate with animals.
I don't write from dreams because I don't remember mine, but I had a fragment of an image left about twins, whose father was telling them how their lives were going to go for the next eight years. I wrote a scene about that, and then another and then another and then another, and after five months I had 732 pages.
The fantasy that appeals most to people is the kind that's rooted thoroughly in somebody looking around a corner and thinking, 'What if I wandered into this writer's people here?' If you've done your job and made your people and your settings well enough, that adds an extra dimension that you can't buy.