Mobility Creep and Counterplay

I know Riot is hard at work trying to make sure more of the mobile champions have a drawback or hefty cost to them. Tristana is getting a small rework, Corki has a more expensive cost to his W, Lucian is forced to max E second for the no cost on his dash, etc. Who are the more mobile champions? Do they have clear costs to their mobility? Inb4LeeSin.