I would like to see some downloadable content made to allow a second player to take control of a companion in split screen mode.
Even if it is only basic, and the main character does most if not virually all of the rest of the work.

I.E even if the second character can only take control of whichever companion the main player gives him/her, and can only wear or use what the other player gives them. Even, if the second player/companion cannot use a pip boy, or engage NPC's in the game...

The Fable series did a poor job, but at least made an attempt...

Would like to know if any of the Game Team have considered this, and if its even possible,
Or would we have to wait for the next installment, and has it even been considered for that?
Would love it if my girlfriend could just grab a controller, press start and take basic control of one of my companions moving, shooting, reloading and changing weapons...

I understand how much the game has to handle already, and how much it gives us, which is why i'd be more then satisfied with the basics above!
I'd also be happy to pay the price of the game over again just to get this privaledge

I think that would be impossible seeing as something like that isn't already implemented in the game. They would have to start from scratch and make that possible. That's just my guess though I'm not sure how hard creating something like that would be. For the PC there's a possibility a moder could create something like what your asking or it could be something simple that they could include in DLC. I am certain though that the developers have no interest to work on this in any of there games and they will keep the game single player as It's always been.

They'd have to adapt the engine for online play, and I'm pretty sure DLC usually doesn't make a major change to the engine. Besides, it would be a ton of work for something that wouldn't be all that great and that energy could be focused on making a DLC with substantial content.

This works really well in games that are linear, like Gears of War. Although it's a nice idea and I would love to see it done decently, I'm afraid it's hard to make work properly in Fallout. I also don't think it can be done with this engine, but maybe in the future they'll do something similar.