*SPOILER ALERT  for People still playing or planning on getting DMC Devil May Cry I'd Advise not looking at this because stuff will spoil the game*

After Talking With My Friend Syed about the new DMC and the story I came up with A theory. If they put stuff back the way they were and didn't edit it...This would of Been a good way to start DMC 3 for a lot of reason. I See Where Ninja Theory wanted to go but because of the "We want a new Dante not old Dante" From the corporations it just throws it off but after thinking and adding up it could of made sense a little *note yes i know Vergil fights Mundus in 3 at the end but lets say they didn't Kill Mundus and instead banishing him to hell and he regains power and Spawns back*

Take these Things out. 
Dante and Vergil Is Half Demon And Angel and make them half demon and human again
Kat Die out at the end or move on with life *mostly dies* 
Give old weapons back *you can keep the new ones because Dante changes weapons every time but with the same effects*
and it can make a good start to DMC3 Why?

The Black Hair thing can stay because in limbo he meets a friend of his father that helps him get Devil Trigger and after that you see his hair whiten and he says "i see you have power but not yet reach your full potential" And as his potential rises so does his hair change. as you progress on you an Vergil work as one and stop Mundus and instead of kill banish to the next world.

Now you stop him the world can see the demons as Vergil says "Limbo is now broken everyone can see the demons" which could explain why you see them out in the open now and all the previous DMC's. Then Vergil talks about taking over and Dante doesn't want that and they fight Dante wins and instead of nearly killing him have the girl Kat block Dante from landing the final blow and Vergil kills her saying "how foolish" using that way to escape to the demon world and have her death words be "i had a child with Vergil but instead of keeping it i gave him away so he wouldn't get hurt or used against us and his name his Nero . The Reason why because it can explain the line in DMC3 will explain the line "its been a year since we last met" and Explain Vergil in DMC 4 and how he came to be. and by that time Dante's hair is fully white and hes reached his potential so in DMC3 hes the Dante we know and then his DT is actually that of a devil and why Nero could use Vergil's sword. 

They Could of added a scene to where they killed Mundus with Dante's guns and say "jackpot" so the scene when they kill joker ("i forgot his real name") it makes sense when they say "just like we use to do before" But hey minor nit pick

This can start Vergil's hate of guns to since he Gave Dante the shotgun and never used a gun after the one time we saw. Vergil's downfall i hope show his progression of getting power and that make him obsessed with it. that way it can make this complete to know that this is what Ninja Theory wanted and why they wanted the old Dante...If that's what there going for

I Could be wrong but hey this is a good guess that's what they were going for. 
I know I'm not 100% on everything so if i miss or made a mistake just comment about it and ill put my input on it to.

This is my thoughts on what i see what ninja theory wanted For DMC To Be.