What are the options as far as melee dps? Is Dragonknight primarily a tank, or is there a viable dps option as well?

I Think Dragonknight is just 1 of the 4 or 5 starting builds.. you can go either dps tank or healz later as I understand it..

Depends on what weapons and skills you slot, and whether or not you are willing to spam your magicka and stamina bars to zero.

All of the classes can be Melee DPS and for that matter, whatever they want, just depends on what else you want.

Dragon Knights have fire powers, many of which are tank or DPS base like,

Sorcerers have a control tree that would help with Melee DPS.

Templars have healing plus a skill tree based around holy light spears that are thrown and used to stab people.

Nightblades have the assassin tree plus the debuffing/control dark magic tree that help.

Dragon Knight seems to be more utility based abilities, and lots are pegging it as the primary melee plater deeps and or tank

Nightblade is the basic rogue archtype, stealth plus, hp drains, poisens

Sorcerer is the mage, with summoning daedra, lightning magic and black status effect magics

with Templar bringing up the rear as a kinda paladin archtype, Holy damage, heals, and lancer abilities

All the classes are viable and function for any role in the trinity. I expect alot of nightblade drain tanks for example

What kind of skills does the Nightblade have?

And how does the stealth work? How does the Nightblade's sneak differ from other classes' sneak?

http://tamrielfoundry.com/2013/09/pax-skill-overview/

The Nighblade does not seem to actually have a boost or anything to stealth, instead the shadow tree gives it ability that help your stealthing around.

These are the skills of the nightblade (doesn't include passives)

http://tamrielfoundry.com/player-classes/nightblade/

THe stealth of the nightblade does not differ from that of other classes. In fact the Nightblade doesn't actually have any skills that make stealth any better.

All classes can do anything. It is just that their class trees may be better for somethings than others. You don't actually have to use the class trees if you don't want to.

Spend some time over here, all 100% developer stuff http://www.tesof.com/topic-summary-of-all-interviews-with-game-developers-educate-yourself

Nice. Thanks.