Some new features are being introduced to make managing your inventory easier.
Item stacks: Items can be dropped as stacks in varying sizes from the inventory. Max stack size can fluctuate between items. Stacks shown in the inventory are automatically made from like items with identical data.
Item tagging: Certain items can allow you to tag others in various ways, making keeping track of special items a lot easier.
Hotbar: Hot bar system for items with use functions. Items with multiple functions can have a specific function bound to a hot bar slot. The first three slots are reserved for equipped weapons.