I wonder how, in general, the existence of hopper will affect other mods. Lets see what they can do:
They can store a buffer of items, well we already have that.
They can send items in different directions, we already have that.
They can pull items in from the world, we already have that.
They can pull items from an inventory, we already have that.
So, nothing new? Well, kind of, but what they do represent is all of that behaviour in a convenient package with none of the restrictions that the mods that can do that add. No need for engines to pull items out, they're much faster than a wooden pipe and redstone engine, and they don't need redstone pulsing or blutricity to pull items from an inventory.
So, traditionally, mods have added things that are more powerful or convenient than vanilla mechanics. How will mods improve on the new Mojang Hopper? How would you improve on it?
What's it lacking:
Direction of input - currently only from above
Direction of output - currently only below and to the sides
How could a new hopper design be made to pull from the front slot of a furnace? Maybe a wrench or crescent hammer could be used to change the input and output sides (right click for one, sneak-right-click for the other)? Would an upside down hopper make sense?