So, on a board that I (used to) moderate, a question came up that generally went like this:

New to Buddhism and am curious on what Buddhism says about our futures. Are things preordained or is it all left to fate?
Generally, Buddhism spends more time thinking about the "now". There's little use in thinking about any other time, because those "other times" are never accessible to you in an experiential fashion, and in Buddhism, that's about all that counts.

In Vajrayana (Tibetan) Buddhism, there is a school of study called Kalachakra Tantra (Kalachakra Laghutantra) that does deal a bit with the future. "Kala" means "time" and "chakra" is translated as "cycle", so "time cycles" works. This school is best known for its development of the Tibetan astrological calendars, but even though it is astrology at work, it deals less with the future and more about the now, using the position of the planets to describe the state of the body (the old "as above, so below" ideology).

Finally, there is the Buddhist eschatological prophesy of Maitreya Buddha, or "the Buddha of the Coming Age". This prophesy is found in a number of sutras, as well as the Pali cannon. It states that after the buddha of our age (Gautama Buddha) and his dharma is forgotten, a new buddha will come again, and teach all humanity how to finally live in a Pure Land...

"Maitreya is predicted to attain Bodhi in seven days (which is the minimum period), by virtue of his many lives of preparation for Buddha-hood (similar to those reported in the Jataka stories of Shakyamuni Buddha).

"Maitreya's coming is characterized by a number of physical events. The oceans are predicted to decrease in size, allowing Maitreya to traverse them freely. The event will also allow the unveiling of the "true" dharma to the people, in turn allowing the construction of a new world. The coming also signifies the end of the middle time in which humans currently reside (characterized as a low point of human existence between the Gautama Buddha and Maitreya.)"1
But again, in the most practical sense, we tend to focus our attention on the here-and-now. The future is only shapeable through karma, and only knowable through experience. Constantly focusing on things that aren't here yet, or knowable, is in many Buddhist scholars' eyes as a waste of precious time.

Going a bit further, your question is only tangentially one regarding "the future". It's more about the question of "do we have free will". In the Buddhist philosophy, we do have free will. Nothing is truly "destined to happen" beyond the continuing manifestation of "the future" moment by moment into "the now", then continually disintegrating into "the past". We as people have choices we make, but as with all phenomena, those choices are affected by the actions we took in the past. Past states always affect the future, and all future phenomena are established by the past (presuming linear time, which we will, since it's the consensus observation). In essence, were there to be no consciousness in the Universe, there would be very little to no chance at something like free will (yeah, I know that sounds rather dumb, but just take it at face value for the sake of argument). All physical phenomena (as there would be only physical phenomena in existence) could be predicted mathematically in accordance with the laws of physics, because all you'd be dealing with is matter bumping into other matter over aeons until everything was so far away from everything else that the Universe would just go dark and die a rather paltry and thermal dynamic death. However, since there is consciousness in the Universe, there are certain bunches of atoms that are grouped together for very brief periods of time (read: "us monkeys") that behave in generally unpredictable ways. As a direct result of this, there is a true randomness to the Universe, and ergo, there can be nothing that is preordained or fated, because there will always be the chance that some unpredictable actor will change things. I can't remember where I heard this quote from, but it's something to the effect of "whenever there are two or more people alive, no king is safe".

With regards to karma; remember, karma isn't "good" or "bad". Karma means "action". It is simply you acting as a player in this reality. You making choices. You doing one thing, -vs- another. So, in this Universe, you take the action, and the effects of that action, from micro to macro, ripple out into the Universe across time and space. You cannot toss a pebble--no matter how small--into a pond without causing a ripple. You can take no action in this Universe without generating changes of state. You fart, and it will affect a star thousands of light years away eventually. That is how physics--and reality--work. That is how they HAVE to work. Now, as far as the thought of "what would happen if I didn't kick Jethro in the ball-sack that night?" or "if I'd just have worn a condom" etc type stuff, Buddhism does allow for other realities and other universes, so in that regard, it can dovetail nicely into the new theoretical paradigms of parallel universes and all of reality being a "multiverse". Essentially, even the actions you don't take are taken into account in the totality of Reality. But as entertaining as it may be to think of such things, it's best to leave that stuff to the likes of String- and M-theorists. I mention it only as a way to see that certain Buddhist ideas can nestle nicely into contemporary theoretical cosmological models.