Lots:
- Siri
- New File System
- Read/Write NTFS
- OpenGL 4.4
- OpenCL 2
- iCloud documents -> like dropbox
- Finder improvements -> like XtraFinder
- More video/audio codecs supported by iTunes -> so I'm not forced to use something like vlc or mplayerx for non iTunes Store videos
- Allow iTunes to store media across multiple drives -> for example music on the internal and movies/video/apps on an external drive
- Let the computer connect to iOS devices over wifi and browse pictures/other allowed content in Finder like a mounted drive
- Launchpad improvements -> better moving of icons, multi icon select, right click context menu, folders in folders
- Improved functionality of Airport Utility
- More options for multi monitor settings
- Further notification center improvements -> 'today, all, missed' like on iOS 7 maybe?
- More notifications for apps the are not running
- Icon/UI re-design
- If it doesn't happen by 10.9 release -> redesign Game center, reminders and several other apps to match the new plain/flat iOS/OSX style
- More new apps
- Maybe a torrent client could come standard with the OS like Transmission
- Clock App - lets you set alarms, timers, stop watch, wake computer at certain times and run task (already exists but could be integrated into this app), etc
- A quality maintinance utility like Onyx
- Trim support non standard SSDs without the help of Trim enabler
- Better screen brightness controls -> like f.lux
- Support for unpacking .rar and several other formats aside from .zip
- Safari improvements
- Better HTML5 Support (pretty sure iOS 7 Safari has better support then OSX Safari)
- Simultaneous Private browsing with non-Private windows
- Fix some bugs like always reloading when going back on certain sites
- Retain zoom in between sessions
- Allow aspects of the new sidebar to be hidden/resized like Shared Link for example
- Give an option to move tabs into the top bar like Chrome
- More advanced syncing (preferences, extensions, etc)
- Fix the slow shutdown :|
I'm sure there's plenty more too.
Some of the things you listed are pretty good but some of them are useless / never going to happen.
Let me ask you a question : are you new to OS X ?
OS X does not need OnyX app-like or any other maintenance app.
It knows how to mange you system. This is one of the best underrated features of Mac OS X. The only thing that OS X really needs is to sometimes repair disk permission, which you can do with the build in Disk Utillity app.
Torrent client by default ? Never.
Slow shotdown ? It's fixed with Mavericks.