This is a nice little collection of some of the biggest analysts and strategists that following the gaming industry. They each have a rank of what they feel will be the biggest things in gaming for 2013.
Personally, I have my own thoughts (in no particular order):
1. Mobile gaming will get bigger and better
2. PC gaming will shrink
3. Apps will be incorporated and used much more on TVs and handheld gaming devices
4. Some game companies will be acquired
5. Social gaming will start to lose its popularity