I couldnt find a thread like this elswhere so i thought id start one. Feel free to lock or prove me wrong on some points. I shall also update this list when more info becomes avalible.
Upon watching the various videos, i felt it nescessary to compile a list, from a modding point of view, as to what Dark Crusade will introduce:
From what I have discovered, instead of appearing from a building each time it dies, when you remake him he just revives where he last died. This is interesting, but not realy practical or fluffy for other races. It can be used for various other things though, but I myself cant see what for
Unless the necron lord is modeled with the nightbringer (as the same way as the avatar is modelled with his 'ashy' corpse), I dont think it is possible in the current DOW engine to change entity blueprints to something else, then back again (unless in SCAR which i doubt).
This is a good one, allowing them to rebuild Necrons nearby. The downside is that they still use cap, so perhaps this is the only way it can work.
The Tomb Spyder's ability to collect carcasses and effectively "store" them as resource to produce different units with opens up a whole new slew of things - unless it's done behind the scenes as simply giving the necron player requisition for collected heaps. Apparently the Tomb Spyder can change Warriors for Immortals and vice versa.
This is one of the newer features that intruges me the most, turning a building into a mobile fortress of death. Although i dont see what implications it can have on any other race, its still a good idea.
In the current DOW engine as far as I know, you cant revive dead troopers in the same way as this without a lot of SCAR.
Kroot and gibs
This might not just apply to Kroot (although rumours are Necrons gain power from gibs). Maybe Apothecaries gain resources back using thier Apothecary saw thing (i cant remember for the life of me what its called).
If there is anythign I have missed, let me know