Base stats:

• Base Mana Regen Per Second decreased to 1.0 from 1.2
• Base HP reduced to 506 from 558.48
• Mana Regen Per Second Growth increased 0.2 from 0.16
• Armor Growth reduced to 3.0 from 3.9
• HP Growth reduced to 75 from 86

[New auto attack vfx]

 Arcane Mastery (New Passive):

Casting spells grants a stack of Arcane Mastery for 12 seconds.  At 5 stacks, Ryze becomes supercharged for [3 and going up to 4/5/6 based on ult rank] gaining a shield that blocks [25 + ~5 per level] (+8% of his maximum Mana) damage and causing his spellcasts to reduce the cooldown of his other spells by Overload's cooldown (4 seconds base, IS decreased by CDR), to a minimum of 0.25 seconds.  Ryze's abilities gain additional strength based on his maximum Mana."

Overload (Q)

Fires an orb, dealing 55/80/105/130/155 (+.55 AP )(2/2.5/3/3.5/4% maximum mana) magic damage to the first target hit. Mana Cost: 30/35/40/45/50 Cooldown; 4 seconds at all ranks  Range: 900   

Rune Prison (W)

Ryze instantly roots a target for 1.1/1.2/1.3/1.4/1.5 second(s) dealing 65/95/125/155/185 damage (+ .40 AP)( 2.5% max mana) magic damage Mana Cost: 60/70/80/90/100  Cooldown: 17.5 seconds at all ranks 

Spell Flux (E) :

Unleashes an orb that deals 50/68/86/94/112 (+ .3 AP )( 2% max mana) magic damage and reduces the Magic Resist of its target by 8/9/10/11/12% for 5 seconds,stacking up to 3 times.  After hitting, Spell Flux bounces to up to 4 nearby enemies and Ryze before returning to the original target. Instances of damage on the primary target after the first deal 25/34/43/47/56 (+ ,15 AP)( 1% max mana) damage. Mana  Cost: 60/70/80/90/100 Cooldown: 7 seconds 

Alternative description from the Champion Update post:

"Ryze targets an enemy unit, blasting them with a slow-moving ball of energy that, after striking the target, splits to damage all nearby enemies before returning to Ryze’s original target, dealing increasing damage based on the number of bolts."

Desperate Power (R)

Passive: Ryze gains 10/20/30% Cooldown Reduction  Active: Ryze gains 80 movement speed and 15/20/25% Spell Vamp for 4/5/6 seconds. During this time, Ryze's spells deal 50% additional damage to enemies near his targets Cooldown: 80/60/40