This will lead to massive drops in global equities due to fears of deflation.
I grew up in Italy during the last few devaluation waves and then the Euro switchover (when prices basically doubled overnight) -- prices of everything except food and shoes skyrocketed, it was really ugly for us little people.
In short, some specific sectors did increase prices dramatically in those years, and probably were the ones felt the most by everyday consumers (food, restaurants, retail etc). I would personally add that Italian statistics on economic elements are historically lacking, due to widespread tax evasion and unreported activity, and suffer from the huge economic disconnect between North and South.
Despite the misleading subtitle, this is a change to the way the yuan is managed and will allow continual (slow) devaluation.