[Update #2]: First part of Minecraft's colossal Caves & Cliffs update has now brought in some very angry goats.
[Update]: Minecraft's next major update will rework, improve and expand upon Caves & Cliffs.
After spending a surprisingly long amount of time in beta testing, Minecraft's rather massive Nether rework has now finally been unleashed. Expect to see a variety of new biomes to explore, hordes of Piglins to either befriend or face off against, as well as the strongest crafting material yet - Netherite.
As you might expect, getting Netherite gear won't be as simple as smacking some blocks with your pickaxe. Instead, you will have to venture in to the lower depths of the Nether in search of ancient ruins, carve them up for pieces you can refine into Netherite scrap in a blast furnace, and then combine four of those Netherite scrap with four gold ingots in order to make a single Netherite ingot. All of that effort will be worth it, however, as once you're done you'll be able to greatly enhance any diamond armor, weapon or tool!
When it comes to the actual details behind all of the changes and additions, including Netherite itself, that you will find over at the official patch notes. The is list is pretty darn big, so I'd advise skipping around to the parts you're actually interested in.
And as a final note, I'll leave you with the newly posted and rather exciting trailer. Enjoy!