Dani, it's definitely a huge source for debate. The apostles were just told that the massive temple they were looking at, the most fantastic architectural wonder for thousands of miles around, would be destroyed utterly. They were astonished and asked two questions. What will be the sign of this destruction and what will be the sign of your return? The monologue that followed answered both questions, but which detail applied to which event is a question that has occupied Christians for 2000 years. To the apostles, the return of Jesus and the destruction of the temple would be simultaneous events, for they believed that the Lord would return in their lifetime. But when the first part of the prophesy came true in 70 A.D. with the destruction of Jerusalem and the temple, it became clear that there was a divergence between Christ's prophesy of near events and his prophesy of his ultimate return. So when I say your guess is as good as mine, I'm not being dismissive. I'm saying that your take on which prophesies apply to which event are as valid as mine are.
Much of the apocalyptic language used, in my opinion, is to illustrate what would happen to Jerusalem and there's a reason that in both Mark and Matthew's account of this sermon, "This generation shall not pass until all these things have happened" is said as a summary after the full prophesy is given. It must not be missed that he said, "all these things", which tells me everything spoken of applies to that generation, but then again, it also has a future application. Studying the Messianic prophesies better demonstrates how Biblical prophesy works. Each prophesy of Christ had an immediate application when it was written that had nothing to do with Christ, but then it had a future application where it foretells the life, death, and resurrection of Christ. When you understand how Messianic prophesies work, it helps you to understand how apocalyptic prophesies work; an immediate application, and then a final application.
I hope I wasn't confusing.