I'm not quoting several people so here is a list of what I would like UA to cover.
Thank you! This is productive.
1: Racial/Class specific feats.
I like the idea. I'm not sure how I feel since I really don't want the 3e situation where each race gets pigeon-holed into a specific 'good' option. Still, I see no reason not to have this. However, it wouldn't be new. They've already done this with deep gnomes in SCAG.
2: Battlemaster Maneuvers.
Battlemaster is a closed system. We have no reason to believe it is getting more maneuvers (although if they start printing new spellcaster spells, perhaps they should add some to help them keep up, although that just leaves the champion farther behind). If you mean another class that uses an analogous mechanic, I am all for it. Although, again, that would be the opposite of innovative at this point.
3: New Monster special attacks.
Yes. Get rid of the whole 'bag of hit points and occasionally spells' argument that I keep hearing. No argument here. They really haven't done much with monsters in UA. This would be a good thing for them to try.
4: Wizards of High Sorcery: (Moon Phase Mechanics) ( I'm a Dragonlance fan).
Eh, but then you have to track the moon phases (or roll randomly, in which case it's just a daily +/-1 or something). The idea sounds nice (and UA sounds like a great place to flesh out the non-FR worlds), but I distinctly recall in late 1e and in 2e lots of little things like this (tracking honor in OA, group magic in Tome of Magic, etc.) that just ended up as more trouble than they were worth. So I think it would end up being mostly ignored, but yes it'd be the kind of thing to try out in UA.
5: More mounted combat.
6: More underwater combat.
7: More aerial combat.
I'd be surprised if we didn't see more wing and water campaign material, but I don't know if we'll see more complex combat systems. That sounds counter to the simplicity that they tried to engender in this edition (and to be clear, from OD&D through 3e, I've never been in a campaign where all the aerial rules were followed, nor where the players could remember when they could attack and when their mounts could).
8: More/Alternate uses for Channel Divinity.
Much like the battlemaster, existing classes are mostly closed systems. For new domains, it's nice when they are actually different. Have the channel divinity abilities not been expansive enough? I seem to recall them being one of the few things that weren't recycled in the new cleric domains (compared to "oh look, this domain grants a different energy type bonus to damage at level 8! So inventive!).
9: Alternate armour rules. (Example would be DR).
So like in the 3e UA book? That kind of alternatives? That would be fine if that's what they saw UA as for. I can understand why they might not. I don't have much to say one way or the other on this one.
10: They are game designers. How about something we've not seen before?
The designers have had the unjoyous task of pleasing people with a new edition which satisfies everyone, sacrifices no sacred cows, and includes all the important cultural touchstones that everyone finds important, yet also fix any perceived flaws in the way previous editions have done them. Plus now we want them to be innovative, but not clearly define how? That's their job? I think that's a little like going into the writer's room and saying,
"I want you to make me a sitcom. It has to be new, fresh, exciting! But also include all the hallmarks of tv for the past 50 years that people expect! And make it surprising! I want twists and turns I'd never see coming! No, I don't know what I mean, that's your job! Just surprise me... but make sure it follows the standard 1 camera sitcom formula! And it better be good!"
11: Will post more when I remember them.
Please do. This finally is helpful.
