Release Date: April 2020
Minecraft Dungeons is Minecraft meets Diablo, and that's not a bad thing by any account. The above footage is from an Xbox event, but it does a much better job showcasing what the game is about than the original reveal trailer.
The idea is your party of adorable little Minecraft figures explores a variety of dungeons built in Minecraft fashion, takes on hordes of enemies, gathers loot, then uses said loot to get even stronger by making weapons, armor, and the like.
The focus is on everything you can't do in regular Minecraft, like explore for a purpose or deck your avatar out in gear that makes them a complete killing machine. It's looking like you'll need that gear too, since Minecraft Dungeons doesn't appear to skimp on the mob hordes. Luckily, you'll get special abilities and magic to help keep you alive too.
It's a clever twist to the usual build-and-craft formula. It's surprising this didn't happen earlier, really, though it's in keeping with Microsoft's desire to expand the Minecraft property in new ways.