The near trend in YA seems to be dystopias, with female protagonists.
Angels are seeing a bit of a comeback in fiction.
In the longer term... I predict sexy bigfoot will become a thing. That, or sexy creature from the black lagoon. All the sparkle of glistening scales will give the vampires a run for their money.
The young teen fantasy/adventure section in Barnes and Noble is packed to the brim with dystopias and female protagonists. Dashner has a new book with a young male hero, about a cyber-reality. and Sanderson released a YA book with dark super heroes.
But what's next. Hmmmmmm. If I knew I'd be rich.
I'm going with altered reality/cyber networks. Maybe Snowcrash style books will make their way back around.