MS buffs & mobility creep

Recently i've seen that Riot has been adding forms of movement speed buffs linked to certain skills to champions that didn't have them before, like Akali's W (from resistance buff to movespeed buff), and now Ahri and Annie (Q and E respectively) and Nidalee (prowl that works with mobs too).

Is this a way you're testing to decrease the importance of mobility in this game? (cos you know, if everyone's got mobility, no one has)

Just a question, i'm really curious about that since i play mostly non-mobile champs like Zyra, Ashe and such.