Why? Well, I don´t know you, but I use redstone all the time, for making doors, or automatic systems.
What is the problem? well, actual redstone complex circuits ocuppies so much space, because to keep two redstone wires isolated, you need a block between, and that block ocuppes space.
So, I have the solution: Isolated wire. You can place two isolated wires without a block between, and they will not touch or interconnect, unless you want that to happen.
Well, I will tell you some characteristics of this great item:
Because it is crafted with 2 redstone and 1 iron, it has more conductivity, and a signal can reach  blocks instead of 15, like redstone dust wires.
It can be placed on ANY side of a block; up, at the sides, and UNDER.
To send a signal up, you need a block where to place the redstone isolated wire.
It can resist water; you can create underwater connections, because it is isolated
REAL Characteristics: Well, in minecraft all the crafted blocks have a similitude to the real life, or have a "Logic" crafting.
To craft isolated wire, we use redstone and iron (conductors), and one piece of leather (isolator).
I like this idea, because minecraft will not need to have new items, or anything, we use actual items.
Well, lets see some images, to make it easier to understand.
As you can see, we use 2 redstone, 1 iron, which brings conductivity (5 blocks more) and leather, that isolates the conductors.
Now, let´s see this new item behavior, and how it works:
The signal does not reachs the second wire
There, the signals reachs the second wire, because we joined it together.
Now, the tdiference between normal redstone, and isolated wire:
We can see that it is not the same...
This yes, but it ocuppies more space:}
OK, now let´s see their behaviors:
The wires are placed like this, depending of the position they were placed ^
I will show you how it would be, if we could see it inside minecraft worlds:
Sorry for bad graphics, I used paint.
You can see the difference between actual up-sending signals and the futuristic ones:
It can be really useful and practic, only placing Isolated wire on a wall, or anywhere!
Well, returning to the main idea, How can I interconnect two isolated wire?
Like this, I will explain:
1) Place isolated wire somewhere else: (blue points are clicks)
2) Click like right side of the image, and then the node will be done. If you do this BETWEEN two wires, you will have this:
And that is all, friends.. It is not a difficult idea, but it is so useful.
Please, share this topic with another people, Mojang MUST read this topic, help!!!
I Hope you like it, Tell me what you think!
Support in principle. Details still need work.