Lee,

A very good point towards the Biblicalness (is that a word?) of determinism. Hard to think of a counter point for me so Let me spit this out and Maybe we can refine it later.

three things to remember.

This nor any other One verse in the Bible Proves that ALL things are forseen. But I do realize that is not your point here either so I will move on

Secondly, The Open View does not neglect the idea of things being foreknown. In the Open View  there are two sense of things being foreknown, one set of actuallities... Things that cannot be altered because God or other agents has determined them and Thus God knows them as facts ahead of time. Then there is the things which are Undetermined and are abled to be influenced by GOd and other agents and incoporated into the plan. These thigns are Foreknown by God in the realm of Possibilities. God is no fool or Idiot, Those things which are not determined He can certainly plan for their possibility and foreknow those contigents.

This applies to this verse surpisingly well. As Open Theists We believe that God created the World planning that we would not sin and that we would follow Him in a real and Genuine Loving Relationship. Yet HE also knew for the relationship to be real and genuine (not a determined robotic programmed realtionship)that the risk of the human not wanting the relationship had to be real, thus including a reality of Possibilities. 

But Praise God He did not make this Choice out of the relationship a one time deal, HE had a plan "Foreseen from the creation of the world." When the risk He took ended up the way it has... God implented the plan He had. He sent Jesus to Die for our sins, And not only for our sins, but for the sins of the whole world. (1 John 2:2) Thus HE foresaw Jesus's death as a Possibilty (though one may argue against this possibility argument simply by saying that the word here is "was" which means that it seems definite, as I said this is a difficult point and I am slowly working it out)

This is further supported by my final point. As you said That the "cross" was foreseen. However this is not what the verse says. This verse States that the Lamb and what happened to him was forseen, Not necessarily How it happened (i.e. the cross). It just says that the Lamb was slain was forseen, Not the Cross. Nor is there any mentions of the cross in the following or preceding verses. you cannot not use these verses to say that The Cross was forseen, only The Lamb that was slain.

 

God BLess,

Chuck