The manga seems to be the most complete source on what is going on.
This thread is probably the best information on the event, so far.
On the vampire side: Vladimir von Helson and the Helson sisters have made it a point to try to kill Johnny Gambino, and Vladimir has stated that he intends on killing Gino as well. Louie and Ian are Vladimir's children. The vampires have been working for the dark elves for awhile, performing assassinations and killing gods. Countess Ambrosia is a new face.
On the dark elves side: Don Luca Kuro, their leader, has been hiring vampires to kill off people and gods, most notably successfully killing Johnny Gambino. He has been very draconian and ordered killing people (most notably one vampire) who failed in their missions. Lots of vampires have died following his orders to kill of gods. He has sent several people to kill Gino, along with the mortal Overseer/Sentinel. His most recent crime was blowing up H.R. Wesley, while Louie was inside. He seems to currently be worked with demons and/or summoning them.
I think that covers most of the major points.