It is an "election", in quotes, but it is an "election" that will come closer to being a real election than any Zimbabwe has had in a long time. Mugabe will no doubt rig it. However, he is running against another Zanu-PF insider who is capable of doing some rigging of his own.
It'll be intersting. I expect Mugabe will pull off another "win", in quotes, but the margins may be such that it will be apparrent to even his most die-hard supporters that his days are numbered .
He holds that country as a Strong Man, basically on the grounds that everyone fears him. As he begins to be seen as weak power will slip away from him quickly.
Unfortunately the vacuum will likely be filled by another autocrat, but maybe Zimbabwe will get lucky and manage to find an autocrat who is at least competent.