Overall, I'm pretty satisfied with the Veigar rework on the PBE.
* It's possible to get more stacks on Q early, when the cooldown is too high to use it 6 times per wave
* Q range is increased. You can potentially poke and farm with it as well. It doesn't happen every time, but it does happen.
* If your lane opponent roams, you can push the wave more easily since Q can hit 2 targets and W has a lower cooldown and mana cost.
* R has a lower cooldown and mana cost. It's true that it has a lower AP ratio, but considering that most of his skills have generally lower cooldowns and he can potentially get more stacks earlier in the game, it's manageable.
However, the changes to his E hurt him quite a lot. Veigar (as he is on live) is very reliant on landing his E, both to set up his combo, but to survive being dove or ganked. With the change, if he doesn't have Flash up it is almost impossible to survive an early dive and landing a stun against a mobile opponent is nigh impossible unless they're preoccupied (which usually only occurs if they are fighting.)
So I propose the following change:
E: Event Horizon - After a .75 second delay, Veigar twists the edges of a ~~375 unit~~ **300 unit** space around the target location for 3 seconds, stunning enemies who pass through the perimeter for ~~1.5/1.75/2/2.25/2.5 seconds.~~ **2 seconds at all ranks.**
**Baleful Strike and Dark Matter become targeted within 500/600/700/800/900 range against enemies within the perimeter, but not on the edges. Baleful Strike cannot strike other enemies while traveling.**
With this change, there is now an actual risk to diving Veigar early on: he can drop his E around himself when you get close, then you can no longer dodge his spells if you stay to attack him. It also aids Veigar's late game, allowing him to stay progressively farther from fights and still deal damage, maxing out at Dark Matter's maximum range (which is also where this change would place the edge of Event Horizon.)
Additionally, it complements the "torture chamber" feel that Riot was aiming for: if you end up in there, even if you aren't stunned, you WILL get hurt if you don't manage to get out quickly.