In addition to the toy box, Warlords of Draenor introduces a number of other updates to World of Warcraft's inventory UI, some of which can be seen in the image above. Each bag, minus your backpack, can now be assigned to a specific type of item. If you want all of your looted equipment to go in your last bag, for example, you can assign that bag to equipment. The above image also displays the ignore option for the new Cleanup system. On your primary backpack, there's a new Cleanup icon that will automatically organize your bags, quickly sorting all similar items together. Ignoring a bag ensures that if there's a particular mess you particularly enjoy, it will not be automatically sorted. The Cleanup option is also available in your bank.
Junk items -- items with no purpose but to be sold to a vendor for gold -- are now marked with a small gold piece. When it's time to shed your vendor trash, you can now see at-a-glance what you should be selling.
In addition, everyone's bank now has a dedicated 98-slot reagents tab for crafting materials and other miscellany. Certainly, that's a better solution than using numerous profession-specific bags such as herbalism's Hyjal Expedition Bag. The reagent tab comes with a Deposit All Reagents button, allowing you to deposit your array of herbs, ores, or whatever else you may have with a single button press. The button is also useful if you're not sure what does or does not qualify as a reagent. If the button takes it, you're golden. If it doesn't, it isn't a reagent.
A screenshot of the reagent tab is included below if you want to see it for yourself, but let's be honest -- it's a grid of empty inventory squares. I think we can all visualize that pretty well.