Fr. Dowd, who gets to eat curry far too often compared to me, is taking advantage of all his slack time this month to continue to explore the nature of God.
He corrects me on a point about potential future being:
Contrary to Tom's statement, I believe that "potential future being" DOES exist. To say that "potential future being doesn't exist" is imprecise: it does not exist per se, but it most certainly does exist per accidens, just as the long quote from Bobik points out. And it fits very nicely with Aristotle (and Aquinas') divisions of Being.
The question, then, is does God know potential future being in a way that He could not know actual future being?
It's not quite enough to say that "actual future being" does not exist either per se or per accidens, so God can't know it. (Also, I think "actual future being" does exist per accidens for future being not dependent on a free will. If I drop a pebble down a well, the actual future being of the pebble in the water exists. But I think we've been discussing everything in terms of future being contingent on free will choices.)
God can't know actual future [contingent] being as actual future being, as I quoted Theodore Kondoleon below. But if He can know it as something else, then I think His omniscience requires that He does know it. Traditional Christian theology explains how He can know it as something else -- by knowing its likeness within Himself as its efficient and exemplary cause, as Kondoleon explains.
Just to keep things interesting, there's a PDF file of "Hans Urs von Balthasar's Method of Divine Naming," by Br. Bernhard Blankenhorn, OP, which looks at Balthasar's ideas of the "super-time" in which God exists and the sense in which He can be said to suffer. It's about as clear an exposition of Balthasarian doctrine I've read (not that I've read all that much), although it suffers as do most such expositions from having to quote Balthasar directly from time to time. (Link via Dominican Life Magazine.)