This is not a common word, so do not expect anyone to know what you are talking about - in America, besides Ian, ;) - if and when you use it. A deck, in english, is always known as a wooden platform behind or around a house for seating on nice days.
I can see where it comes from though... A deck of cards is like a stack of images, and so is a power point. Also, being on deck, means you are next in line.