Dragon type needed a nerf badly. The only type that even resisted it before was Steel, and even then Dragons could just run over Steel types with Fire/Ground moves. Heatran@Air Balloon is pretty much the only way to even hopefully counter Dragon types in the Gen V metagame (at least it seems that way to me).
Poison type needed the buff, as it's only SE against Grass pre-Gen VI. About the only good thing about it was Toxic. --- That is not dead which can eternal lie, And with strange aeons even death may die.