#1. Improving Performance and Stability: Even though High Sierra runs fine on my MacBook Pro. You can always get better performance and stability out of an OS, and fix the issues that plague other users and machines like the iMac Pro fan performance issue!!! I think they can also optimize APFS better, giving all of us with SSD's a little more speed and efficiency. Also with APFS, if they would get the support for Fusion Drives released that would help all those people with Fusion Drives out. I mean come on Apple, it has been long enough! I have a feeling APFS will be officially supported on Fusion Drives with macOS 10.14!
#2. Homekit Support: Either a dedicated Home app like on iOS, or being able to control everything through Siri on macOS. Preferably both as we all know Siri has some serious issues and to me at least seems even more crippled on macOS. I really think this would make A LOT of users happy.
#3. Apple Music App: Dedicated Apple Music app. No more integration in iTunes.
#4. iTunes: Speaking of iTunes, can we finally just get a better version of iTunes? iTunes has been a mess for the past several years. I think the last time iTunes was actually pretty good was with Snow Leopard.
#5. Health App: Dedicated Health app. (Off topic, but lets get Health App on the iPad as well!)
#6. Siri Overhaul: I mean this goes across ALL Apple devices obviously, but Siri needs a serious upgrade.
I really hope that macOS 10.14 turns out to be the new Snow Leopard! That was the last truly amazing across the board Apple Operating System. Lets hope with Apples focus on performance, stability, and getting rid of all the bugs that this release turns out to be the next truly amazing across the board Apple OS.
@chabig, stop being rude. This site is called MacRumors for a reason! We guess and speculate on tons of issues on this site. If you do not like this thread, then I would imagine you probably do not like most threads on this site and therefor you should stop coming here. Simple as that. No need to have such bad form towards the Mods or anyone on this site for that matter!