Yorick changes
Most important- R
Maiden is marking the enemy that she hits, and when Yorick attacks the marked target, he deals a bonus percentage magic damage. Now it has 2 second cooldown and deals 9% max health damage
But on PBE it's changed, and it doesn't have any cooldown, but deals 4% damage. So probably AS Yorick will work pretty well, with Trinity, Botrk, etc.
Q
Mana Cost will be reduced from 25 to 20
It no longer doubles healing when Yorick is under 50% health, BUT now it heals by an additional 4% to 8% missing health, reduced by 50% to minions. Overall he heals more than earlier.
E
Cast time will be reduced from 0.33 seconds to 0.25 seconds
And E has more gravity, it doesn't change mechanics, but it looks better
Runes
Conqueror is still a good choice, but probably Lethal tempo will fit great to his Ultimate changes
Flash/Teleport is best choice
Items
Cull is Cool. If match-up needs that u can take Doran's shield.