Every year one genre seems to take the charts.
I'm hoping it'll be not one specific genre but a further diversification of styles and fusions.
Seeing radically different kinds of music topping the charts from week to week. One theme that will probably dominate across all genres like it has in the past though.
On that front I think music is going to be invigorated anything electronic or sample based with the minimum number of members and gear to make touring cheap. Most labels love it as it is good money, and I don't see a return to big bands, buses and lots of gear any time soon.
Personally, I'm hoping Riot Grrrl will make a comeback.