With the more general release of class and (some) weapon skill lines, it is possible to start identifying some of the ways which ESO combat proposes to work.

One of the things I have found most interesting in the released information is the situational nature of pretty much every ability. There is virtually no abilities that are simply 'just do damage'; almost every ability has a status effect such as a DoT, snare, knockback or a combination of such effects. Indeed, there are situations where the 'baseline' abilities are very situational, such as for Destruction Staff, which (if we follow DnD traditions about 'touch' attacks) has a melee attack as its first ability; very odd for a ranged weapon. (See: http://tamrielfoundry.com/2013/09/pax-skill-overview/)

Now, I may be applying conventional MMO wisdom here but, generally if an ability is designed to apply a status effect, it is rarely the most efficient and effective way to apply direct damage to a target. With this assumption in mind, I tried to work out why exactly all of the abilities are so situational. My conclusion is this: it will be the normal and heavy attacks of your weapon which forms the majority of your damage, not the abilities on your hotbar.

I believe this conclusion is in line with some of what has been said by developers in interviews, but I cannot remember exactly when or where. However, it does make a LOT of sense for a few reasons. Firstly, as alluded to above, it means that 'mages' with magical staves are able to throw fireballs or lightning bolts, instead of relying on a touch attack to start with. Secondly, given the limited number of abilities that can fit on the ESO hotbar, it means that there is no need to waste a slot on your basic attack. Thirdly, in a game without a rigid class structure it importantly ensures that weapons fill the same role for every playstyle; whether you are a sword swinger or a spell flinger, a weapon upgrade represents a direct DPS improvement, not just a stat stick, ensuring that no one option is better or worse than the other.

If the conclusion is true, then it raises some very interesting implications. For the player looking for maxdps, instead of seeking out the most damaging abilities, it may be better to slot abilities that instead improve their weapon attack in some manner; good examples of this being Haste or Weakness to Elements (see: http://tamrielfoundry.com/2013/09/pax-skill-overview/) or possibly even Surge (see: http://tamrielfoundry.com/2013/09/skill-overview-sorcerer/) depending on how Power interacts with weapon damage. While this sort of buff-centric playstyle is not unfamiliar to Melee or even Archer classes, ESO seems to make it applicable to 'casters' as well. Indeed, if the majority of DPS comes from the weapon's normal (or heavy) attacks, a Nightblade with a Destro Staff using BOTH Haste and Weakness to Elements may prove to be one of the highest DPS options out there.

That being said, this is merely uninformed theorycrafting. However, I am interested to hear what people think of my conclusion and what implications it might have upon the game.