User blog comment:TheTobarMethod/A New View On ADC's IMO/@comment-98.246.3.43-20130211054252/@comment-128.230.241.31-20130213184430

Vayne's Q ENHANCES the autoattack that she's about to put into the nearest living thing. She is autoattacking, not casting a tumble at a target. Tumble simply enhances the autoattack.

Corki's Q is a AoE Burst that gives him a chunk of magic damage and a trinity force proc. He is not autoattacking, he is casting an ability.

Ezreal's R is a global AoE chunk of burst magic damage that he uses to supplment his damage from autoattacks. It's not doing anything to enhance his autoattacks (other than indirectly giving him attackspeed from his passive). He is CASTING his R.