I don't necessarily expect to get what I hope for, but I hope to geta couple of simple things.
1. That they stop with the un-thematic and USELESS 10 minute restrictions on things like flight and Goliaths using large size. Goliaths aren't shapeshifters and if you have wings you can fly. It doesn't break the game especially at 5th and higher where many parties have someone or several someones who can change size or fly anyway. The 10 minute restrictions, even if they made it 1 minute, detract from the fun for a reason that doesn't exist. It's a bad and needless mechanic. They assume that this restriction will curb abuse. It won't. 10 minutes (or one) is plenty of time to cheese many challenges and flight or reach are not out of line with the kinds of abilities that characters get at early levels anyway.
2. The other thing I strongly hope for is a good fix for the Monk. Give them a fighting style at 1st. The Unarmed Fighting Style could fix the damage for unarmed strikes. If they do this, remove needless Ki point restrictions on abilities like Step of the Wind, that don't deserve that requirement, and if they FINALLY, stop making USELESS sub-classes, the monk will feel like he measures up in play. Over and over, WoTC has published sub-classes that are empirically weaker than what the monk already has without using his subclass. ALL of the official subclasses are very weak and most make the monk worse not better to play. They assume that Stunning Strike is so strong that it justifies this, but it doesn't Stunning Strike is not that strong and even if it was, that doesn't make penalizing the rest of the class progression a good answer. So, give them actually strong sub-classes that do justice to the themes, or at least ones that compliment the monks strong points. Then make Unarmed Strikes a weapon type that can have mastery properties. Everything I've seen so far says that those are very popular in play-testing so maybe that at least will happen. (End of Rant).