Unfortunately, im happen to be EU player, so i can only judge by using template character at this moment and can only take a peek into unmorphed skills.

So i summ up what i saw from my point of view. If you guys have anything to add or have any info on skill Morphs (if they differ from what we have now on live) please add this here.

Assasination Tree

Actives

Soul Harvest - Nothing changed with it's effects. Damage seems to be scaled very nicely.
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Assasins Blade - Nothing changed with it's effects. Damage seems to be scaled very nicely.

Teleport Strike - Now have insta cast time. Damage seems ok. But no longer give 30% increase in damage to next attack ? Expensive magicka cost. Any use for this now since it is also no longer stuns players ?

Blur - Nothing changed.

Mark Target - Now give flat Magic resistance and Armor reduction. No longer reduce your armor and resitance any more. While this is good changes, skill are now Major Fracture which prevent it from stacking with Weakness to elements from destruction stuff tree and similar debuffs so effectivines are pretty much questionable.

Grim Focus (previously Haste) - No longer give boost to Light and Heavy attacks speed. Gives Minor beast which grant 8% buff to damage. Not that big buff like ZOS pomised. If 8 light or heavy attacks made while skill is active skill transform into Assasin's Will. While there is no info what it actualy is, it says it also spawn Spectral Bow which deals quite nice damage. Probably the only viable tactic for NightBlades to weave light attacks is going into Crushing shock build.
However , at the same it makes that build somewhat less effective for NightBlade bcoz it no longer give light and heavy attack speed boost.

Any info on it's morph ?

Passives

Master Assasin - Nothing changed. Still nearly useless passive which MIGHT give profit 1 time per fight max.

Executioner - Nothing changed. Still completely useless passive which give redicilously low ammount of Magicka over redicilously long period of time under unacceptable conditions (you must land a killing blow and you have to do it with Assasination ability).

Pressure Point - Nothing changed besides the fact that all crit bonus skills and set bonuses become weaker. Tooltip have an error. It show same ammount of bonus on both values for "Each ability" and total value.

Hemorrhage - Added buff to nearby allys which boost their crit rating every time NightBlade land a critical hit. Crit rating buff, however, is so low that it doesnt even worth mention.

Shadow tree

Actives

Consuming Darkness - Seems completely reworked. Unmorphed version no longer deal any damage. However it now have both synergys which was devided betwin old morphs. Synergy now give ally both invisibility and quite nice healing.

Can any1 provide info on this Ultimate morphs ?

Shadow Cloack - Nothing seems changed (expect its probably completely broken again like with every other big patch ). Heavy Magicka cost.

Veiled Strike - Nothing Seems changed.

Path of darkness - Speed buff no longer stack with other Major speed buffs like Rapid Maneuver. Sad part is that any other NB speed buffs like Cripple are also Major buffs so you cant even make any synergy with your own skills......
Nothing changed with usebility of this skill. Still way to heavy Magicka cost compared to Damage output and litle use of this skill. No synergys was addedd.

Aspect of Terror - Nothing seems changed.

Summon Shade - Damage reduction no longer stack with other minor debuffs which makes it completely useless in PVE bcoz tank usualy use Low Slash whith same debuff. Still redicilously low damage and heavy Magicka cost.
For me, that skills now looks completely worthless in PVE.

Can any1 provide info on it's morphs ?

Passives

Refreshing Shadows - Nothing changed.

Shadow Barrier - Now provide flat Magic ressistance and Armor buff after activating any shadow skill instead when getting out of stealth or invise. Effect can be insreased by equiping pieces of Heavy armor. While this change seems quite good and i realy like the fact it have synergy with Heavy Armor, the 4 second duration and the fact it is Major buff which make it unable to be stacked with any other similar buff makes it quite questionable.

Dark Vigor - Nothing changed.

Dark Veil - Nothing changed.

Siphoning tree

Actives

Soul Shred - Damage seems to be scaled poorly. It is now deal less damage then Soul Harvest. Other mechanics did not change.

Any info on it's morphs ?

Strife - Magicka cost seems to be heavily reduced.

Any info on morphs ?

Agony - Nothing changed.

Cripple - Nothing changed besides speed buff no longer stack with other major buffs which make it impossible to create any synergy with NB's own skills.

Siphoning Strikes - Nothing changed besides you will now feel how much it gimps your damage much better.

Drain Power - No longer give buff depending on the number of target you hit. Give flat 20% weapon damage increase instead if atleast 1 enemy hit.

Any info on morphs ?
That seems pretty wierd to me. Why does every other class have their buff skills reworked to make synergy with both weapon damage and spell power, but NightBlade was left with Weapon damage buff only ?

Passives

Catalyst - It is just........... Give 8 ultimate after drinking a potion.... So basicaly it give 8 ultimate every 30 secs MAX (or 15 secs if you have all 3 jewels enchanted with potion CD reduction). No more buff to potion effectiviness.
HEAVY NERF to nightblades.

Magicka Flood - Nothing changed

Soul Siphoner - Nothing changed

Transfer - Nerfed to make it give same 2 points of Ultimate when you deal damage with Siphoning skills from every hit to once per 6 seconds.


So what we have in total ?

All this so called "complete rebalance" appear to be just those few skills changes they mention on ESO LIVE.
NightBlades recieved few very little and very questionoble buffs while was heavily nerfed once again.

Still very little synergy. Actualy no synergys at all on normal skills. Just few of them on Ultimate which are now pretty hard to generate.

I like that Shadow Barrier passive now have synergy with heavy armor. I wish there would be more such synergys in other passives amongs all skill lanes on all classess.