My 3D2Y Predictions for Zoro:

His hair will possibly be more stylized
His Style will become darker (from living with Perona and Mihawk for 2 years) I think Perona will make his clothing haha.
He'll don a few new scars, some will be visible (like on his face)
He'll accessor more, More earrings, neckless, rings (the neckless and rings maybe because he's picking up more from mihawk)
He'll be slightly more buffer, but not too much, just to show off his training.

I also think, he wont beat Mihawk in the entire 2 years, but he will by the end of the series.

2Y Luffy Prediction

Nami is next.

7 more days!