Unfortunately I don't know, so I can not tell you something. Sander93 might be able to give more insight, I often miss some stuff as well.
One thing that is more or less confirmed is a rebalance of heavy tank timing which got a bit messed up after the last patch and caused the "heavy only" meta that we currently have.
Otherwise I can only send you to the forums. OST T4 was a pretty hot discussion topic where people agreed that something should be done about it. There's a vivid Panzerwerfer discussion, Ranger vs Paratrooper, SOV field HQ... It's not obvious what will be taken into account by balance team, they also have to fit their scope and be able to do it in their free time. Also Relic does not allow drastic changes anymore, so most things will be stat changes, abilities and/or upgrades etc.
I wonder if they will add the cougar.
The cost of panzergrenadier reduced to 300.
Improve the bumbar.
But will they do anything for January?