The question is simple: which difficulty do you hope the additional normal and veteran versions will have?
I would describe me and my guild as something like semi-ambitious casuals. Both normal and veteran dungeons of the base game are more or less a faceroll, with only a few of the vet versions even needing a healer. However, the DLC dungeons are a totally different thing and while we have a few pretty good players, it is still very rare and a subject of applause in our guild if people manage to beat the veteran version of the latest dungeons. For the IC dungeons it happens sometimes, but is also rather rare.
Therefore, I personally hope for a normal version that is set at a slightly lower difficulty than the newest dungeons and a vet difficulty somewhere in between the base game and the DLC dungeons, maybe with a hardmode that sets the last boss fight at the level of the current vet Hist dungeons.
Ideally I also hope for eventually a third tier of difficulty, but since this seems to be out of the question at the moment, I would love to see the newly added dungeon parts to cater to the casuals who know about their build and abilities.
Elder Scrolls Online: concept, Gold Sink & Trash Mobs 