Two new character classes: the Assassin and the Druid.
A fifth act taking place in and around Mount Arreat in the northern Barbarian Highlands, with an additional act boss, Baal.
Many new weapons and new pieces of armor:
Runes can be placed into sockets and provide different bonuses from gems.
Using Horadric Cube, needed quest item for Act 2 and runes as recipes, one can empower the items.
“Crafted items” are very similar to rare items but they cannot be found in chests or dropped by monsters. They can be created with the Horadric Cube and the right ingredients. They have 3-4 fixed properties that will enhance the items.
“Runewords” are very powerful bonuses that are granted to an item when specific runes are socketed in a specific order.
“Jewels” gain the same random bonuses that items can. These can be placed into sockets. They have the same effect no matter what the base item is. Unique jewels FFXIV Gil are “Rainbow Facets” which have different bonuses to a certain element.
Ethereal items that are normally more powerful than their standard counterparts, but they have lowered durability and cannot be repaired.
Charms that can be kept in the inventory and provide passive bonuses.
Class-specific items that can only be used by a certain character, e.g. Claws for an Assassin.
Additional unique and set items, including class-specific sets.
An expanded stash for storing items—two times the size of the original stash.
An alternate weapon/shield/spell setup that can be switched to via a hotkey in gameplay.
Hirelings can now follow the player through all the Acts. They can also be equipped with armor and a weapon, can gain their own experience (originally they leveled up with the player), can be healed by potions, and can be resurrected when killed.
The game can now be played at 800×600 resolution, up from 640×480.
I’m not sure the html codes to use to put all of that in a quote box so forgive me if this is annoying to read. Most of this already seems to be in Diablo 3 but I think the reason LoD seemed so massive before I actually looked at what all it included is just how much it changed the game. What they seem to be proposing now is changes to bring it in line with what the console version has and a new act/class. Not much in the way of advancing the game though, really.