1. One of the messages of the Bible is that we live in a world characterized by spiritual warfare. Like most other religions, Christianity maintains that there is a fairly well-populated spiritual realm, and that some of its inhabitants do not have our best interests at heart. I think this is important to keep in mind when we look at Bible prophecies. I don't think the Bible lays out any kind of future history so that we can determine beforehand how events will unfold. If it did, then the malevolent spiritual world would know exactly how things will happen as much as we would, and would be able to use that information against us, the same way that a military would be able to use the captured plans of its enemy against them. In Christian spiritual warfare, however, it's not possible to give any information to the good guys without also giving it to the bad guys -- even if you encode the information, the knowledge of how to decode it can only be given the same way as the code, which means that both sides would be able to decode it.
Jesus' atoning death is an excellent example (it often functions as a paradigm in this way). We know that the malevolent spiritual world had a hand in Jesus' execution. If such evil spirits, or whatever you want to call them, knew that Jesus' death would atone for the sins of the world, do you think they would have instigated it? Of course not. Thus, the prophecies are obscure enough that the ancient rabbis were not able to put together a "future history" of the Messiah suffering, dying, rising from the dead, and thereby atoning for the sins of the world. Now afterwards we can see how they say these things. But if they laid it all out, then the malevolent spiritual world would have moved heaven and earth (ha!) to keep Jesus from dying. Thus, I think Mel Gibson's portrayal of Satan not wanting Jesus to die in The Passion of the Christ is incorrect. Satan was no doubt behind it all, grinning like a maniac, and then when Jesus gave up his spirit, Satan's ultimate victory turned into the most crippling defeat he could have experienced.
So I think the end times prophecies should be seen in light of this. We can do our best to try to understand them in a systematic way, but if we were able to put all the pieces of the puzzle together, so could the malevolent spiritual world. To ensure that they cannot, God wrote the prophecies so that we could not either ... until they actually happen. In other words, Bible prophecies are primarily meant to be understood by (and thus to encourage) those who are living through the events they describe.
2. Now some non-Christians may think that in all of this I am merely making excuses. The Bible, they might say, does not give clear and direct predictions of future events by which they could test it to see if it is really true. All I'm doing is making excuses for this lamentable situation. In response I make two points: first, my contention is that Bible prophecies are not written in order to provide "testable" predictions in the same way that contemporary science does. Thus, this objection is essentially that Bible prophecies fail to meet an objective they were never intended to meet; and this is neither rational nor convincing. In saying this, I do not at all intend to demean the scientific method or the great value of science. What I'm saying is that it is invalid to take a method used in one field and apply it indiscriminately to another field that has different goals and purposes.
Second, it simply isn't true that such predictions have to be clearly understood before their alleged fulfillment in order to have any value as actual predictions of future events. The predictions in the book of Daniel are an excellent case in point. Daniel predicts the rise and fall of several empires, including Greece and Rome, in very metaphorical terminology. The fact that it describes this with metaphors does not mean that it doesn't clearly predict these events; indeed, most Bible commentators who reject biblical inspiration argue that Daniel must have been written after Alexander the Great and the rise of the Roman Empire because the descriptions are simply too accurate. But I very much doubt anyone could have laid out precisely how these predictions would be fulfilled before they actually were, based solely on the prophecies.