These are the 3 necromancer skill lines revealed to us today. 1 tank skill line (bone armour), 1 healer skill line (soul mending), 1 DPS skill line (elementalist)
So they're sticking to the 1 skill line per role thing they did with the warden.
Not sure how I feel about that. Although warden tanking and healing were fine, magicka DPS was putrid because there was a lack of skills to choose from.