"Πρόκειται να σε περιμένω."
Translation:I am going to wait for you.
"Will wait" is future simple which is θα περιμένω. It's not the same thing even if it practically means the same thing. It's a different structure and translating it otherway is not correct.
I was just mentioning the same thing on another sentence. Here we use a new chapter for the Greek to show another kind of future "προκειταί να". It is future as a planned action or intension and that's just what "going to" reflects in English.
It is quite commonplace in spoken English, however, to express deliberate, planned and intentional future action by placing an emphasis on 'will'. Hence, 'I will go to town today' stressing 'will' indicates either the implication that I intend to go despite any objections, or that, having previously wavered, I have decided to go.