I think that's what everyone expected. Things look good already on the Xbox One and if it kicks it up another 20% or so that would be even nicer. (I remember seeing that number hinted at with the GPU somewhere.)
But there is no way it's going to make things worse. Plus having a common API over all platforms just helps development. And puts more pressure on Steam to make their software better.
DX 9 has largely been the norm until quite recently. Looks like DX 12 may takes it place for a while.
PS I wonder what would be the min hardware for DX13. Probably some major changes before that comes around.