Well after the pictures from White Dwarf appearing online, more pictures of the Ork Battlewagon are appearing.
The Bell of Lost Souls has had a nice spread of pictures of the model.
EDIT: Post removed from BoLS… See all the pictures on Warseer.
These give a much better idea of what the model is like.
It does look like that a Deff Roller could be fitted onto the front and there is the potential for a range of turrets as well.