It is even worse then meh, alow me to explain.
First of, this crystals are unrealiable and super easy to counter, the majorty of the game he won't be using them simply because teamfights mostly occur in the mid lane, where he has no crystals. Also, the crystal dont help him with ganks at all, and even force him into the jungle role, simply because lane skarner now doesnt have a passive basically. The crystals themselves arent all that exciting either.
The MS, AS and mana regen that e crystals grant are nice, but then again skarner wont be around them for the majority of the game, again losing his entire passive.
And because the crystal grant such significant bonuses when he actually is around, riot decided to nerf literally everything else.
First off base stats.
His base movement speed has been reduced from 345>330, This is a HUGE nerf, because for a champ with no instant gapcloser he needs to rely on his MS to get onto people, nerfing this essentialy makes it ALOT harder for him to gank AND teamfight.
His health per lvl has also been nerfed. I dont know the exact numbers, but i did calculate that @lvl 18 skarner now his 200 health less. For a champ that is supposed to be a tank, and needs to be tank to be able to survive getting to his targets, this is also a giant nerf.
Secondly his passive:
His passive, crystalizing sting (the stun, a reliable form of cc and damage), has been replaced with a clumsy unreliable easy to counter passive. His old passive alowed him to disrupt multiple enemies in teamfights, help him with ganks, duels, clears... Skarner gave his team so much crowd control in lengthy teamfights (wich are his speciality) that the removal of this passive for such a worthless passive. Its just not good. Also his new passive, he just cant decided where he uses them, it gets chosen for him, giving him less,options.
Up third his Q:
Oh man where do i even start on this, one word to describe it: destroyed
Here is why: most importantly, the stacking Movement AND Attack speed buffs are gone. This is a nerf that is just to hard for words to explain, skarner needed this MS for him to stay on top,of his opponents. After he slowed them with E and closed the initial gap with his W. Also with his old passive his Q was his main tool to stun enemies, now that is gone, so from (Ms, As, Dmg and stun) it went onto (Dmg) like really? His Q was so versatile, it was just what made him good. Dmg is overal the same, it is more if your built him ad, (wich nobody does, or only a few). Then, his Q now only gets 0,25 Cd of it upon hitting monsters, although the cooldown, is lowered, it still affects his clear alot.
Next, His W:
This is a change that i actually really like, his shield now scales with max health, opposed to flat shield (kinda like nauti shield rework) this made him alot tankier in teamfights, and really helps out his kinda underwhelming late game. This change is probably imo the only change that should reach live.
Now, his E, the change that helps his ganks, (sometimes) and screws over his teamfight.
The old passive has now kinda been placed on his E, when he now hits an enemy with his E, they are slowed as usual, but if skarner then lands a AA, the enemies are stunned for 1 sec, this makes his stun alot easier to hit, BUT only on one (maybe two) champs, instead of being able to disrupt the entire enemy team. Now they made his E, wich was pretty shitty on live, into an ability that makes or breakes skarner, if he misses it, he is screwed, if he hits, it is only a bit better then it is now, but then again, only one person (most likely)
Lastly his R:
Not much changes here, only the bonus damage from his old passive stacks is removed.
So as a conlcusion, i REALLY dont like the change, they took away what skarner stood for to me, a fast tank who is super sticky, and completly disrupts enemy movements in teamfights. He could pick a target and literaly stay on top of them due to his Q and W MS, and his stun. Wich is what he was desinged for, a sticky predator that hunts you down. I beg your riot pls dont make these changes hit live, i know you put alot of time and effort into it, but it just isnt good no matter how you look at it. Pls dont nerf my FAV CHAMP OF ALL TIME,
RIP 
Ps: srry for bad english, it is late and english isnt my native language.
