Yorick is my main, love him! ♥ He's a GREAT (top) laner, dealing lots of damage. But you gotta be careful with him, better first focus on killing minions for money and then try to deal damage to the nearby enemy. You can't kill the enemy at once, but you should have patience with Yorick. When the enemy is weak, take out your best and quick, you've got yourself a kill now ;)
Yet, his mana will run up very quickly, make sure you don't waste too much for minions. Better don't waste any on them.
I just got Yorick a few weeks ago so I dont know if tehre are any changes, but I read at a forum that he has less good potions, but I think they're not even needed ;) However, I love this guy, highly recommended!