I've noticed that whenever we see a mage depicted, they seem to be usually holding a staff.

Do you think staves will provide certain kinds of passive buffs for spell casting?

It's quite possible. I mean in normal TES games such like Skyrim, staffs had magical abilities sometimes that let them case a certain spell without using magicka. So it wouldn't be to hard to assume that could be possible, however there is no official information on that.

Well, didn't the devs say that you can choose to wear any weapon / armor without being penalized?
That would say no, you don't get buffs for wearing a staff.

This is true any class can use any weapon, but that doesn't mean that if I'm a warrior and I am fighting in a PvE area and a staff drops from a monster and lets say that it's a magical staff, well there could be certain magical attributes that would allow certain spells to be cast more often or given the ablity to cast a spell using the staff as a conduet. Instead of your magicka.

Staves, just like any other weapon, will define you play style, granting you abilites and their morphs. In the video you can see fire/lighting ones and a green glow (perhaps healing) one

Its not cooldown mmo where weapon is just nice skin with some stats on it, its TESO

Agreed, which is why it would make sense that it may have an ability to use some spell without using your magicka just like in Skyrim, Oblivion and Morrowind.

Depends on design, we dont know really, basic attack wont use magica and power attack should use stamina. But then both can be "whack him with the staff" and real deal would still be special abilities that come from staff but are placed on hotbar.. and eating mana. Beta will tell

Very true, we won't be able to fully know till beta, which I can not wait for..

I suppose my question is, will there be the option to define a playing style around using no staves or weapons at all, only spells?

In the single player TES games, the progression path for a mage character usually focuses on finding spell tomes (or buying spells from merchants) and gradually becoming more powerful as you learn new spells. In some other fantasy RPGs, spells are treated more like perks, and you automatically learn one at each level up, so it becomes more important to find staves and loot items with passive buffs.

I can imagine for PvP balance purposes, mages might be limited to a specific number of spells at each level, treated as perks, rather than being able to find spell tomes at any level. However, I understand we also have the limitation of six action bar slots to use in combat, so perhaps we can find spell tomes, but must choose only a few to be available in the action bar at any given time?

Well, they took "whack him with the staff" out of TES after Morrowind. It stopped being a regular weapon, and became a charged "spell-shooter."

I would think you would be able to, it's just that a staff will give you more stats possibly, as well as a possible "standard" attack. Without a weapon you may not have a "standard" attack as well as a stat loss..but they may be able to make it so that a mage's "standard" attack could just be a spell and you wouldn't have to have a weapon in your hand. Also for all of your magicka draining abilities that you wouldn't need a weapon because lets say for example your a paladin and you can heal but you have a sword and shield (You shouldn't need those two items to be able to cast a heal) so I'd think it would work more like that. but again not sure because we haven't played the game yet.

Hm, I think most people guessing at this stage since the game is in early alpha, and it's hard to tell without proper evidence and more Videos from Zenimax.
A stave could also be a blunt weapon, or an enchanted staff with a certain spell for example fireball or lightspell - so maybe we've magical enchating in ESO too.
Perhaps, we can create our own spells within limits as we did in Oblivion/Daggerfall.

Like with lift-click attacking, the staff will probably shoot out a firebolt or something like that instead of the typical melee-swing of a sword.

Ah, one can but hope.

It'd be nice.