Xiaomi devs have created a unified thread for all the features currently in development for MIUI 10 and MIUI 11, as well as a table of features that are under consideration.
There aren't many groundbreaking features included, but at this point it's more about refining something already good.
The system-wide Dark Mode, introduced in the Mi 9 will make its way to all MIUI 10 devices.
A new setting will allow you to view the lockscreen after an authentication, instead of going directly to the homescreen. Xiaomi will allow face unlock and fingerprint unlock to work simultaneously. There are also new sound effects.
You will be able to wake the screen up by using voice commands.
Those are all features in development right now. Xiaomi also listed features that will enter development in the future like Child Mode, a recycle bin for photos, automatic deletion of an APK file upon installation and more.
For the complete list of features, head on over to the source link.