It is said that God knows all things but (in the way we interpret this at first) this would mean that God already knows who will be exalted and thereby meaning that we are all predestined to make the choices that we do.
However I think that there are numerous ways of looking at this (the correct one of which, we are unable to identify in mortality) I think that Heavenly Father sees this differently as an exalted being. He may be able to know all possible outcomes of every situation simultaneously. He also knows the relative likelyhood of each outcome. The only variable is the agency of His children.
Another possibility is that God can look at the universe he created without the restriction of time (or by manipulating it somehow. Remember that God created the laws of the universe and must abide by them. Once you get into it, it all becomes very interesting from a Physics point if view)
Does Heavenly Father know right now whether I will be worthy for exaltation in the celestial kingdom at the last day? I do not think a straight yes or no can be given.
My destination after this life will be a result of the choices I make while on this Earth. I think that God knows all of those choices but cannot know for certain which I will choose when presented with them.
After all: how can hope be a Godly characteristic if God knows exactly how everything will play out (thereby rendering hope meaningless. How could God hope for something he knows will not happen. It would be like us hoping the Titanic will not sink at the end of the film)
This is all speculation of course. I don't think we can really know until we pass from this state of mortality.
Nevertheless it remains true that the existence of Satan was necessary for the plan of salvation to succeed as there has to be opposition in all things.
