Weather Effects and Much More!
Many of us are waiting for new opportunities to create interesting mods for Minecraft: Bedrock Edition, and the developers are listening to their players! Recently, version 1.7 was released, which brought the scoreboard system, very useful for maps and servers. And very soon, new interesting and useful functionalities for creating various mods will appear!
If you dig into the game files, you can already find a folder called definitions, which contains files responsible for displaying creatures, their animations, as well as block and item recipes.

"What does that give us if the files can't be edited?" you might ask. Yes, currently editing these files is pointless, but the developers promise to move them for editing into behavior packs and resource packs.
"Well, they'll move them, but what good does that do me?" There is a point. Right now, you can't add your own block or item recipe to the game. But animations and other mob-related things will be useful for map and add-on creators to completely change a creature's behavior.
And if it becomes possible to create your own creature, that will be even more useful!
Additionally, Tommaso Checchi announced that we will be able to edit weather effects through resource packs!

Exactly what can be edited is unknown. We think it includes sun glints, fog distance, snowfall "intensity", and more.
Some things may be added in the next beta, while others will be announced at Minecon 2018!
Tommy even jokingly tweeted "we're going to add a battle royale by removing crafting and mining." We hope that's really just a joke.

The announcement of the new update will be on September 29. The update itself will be released in spring 2019.