In short: “No, the election will likely not be ‘hacked', and yes, you should vote.” Beyond that, the answer becomes more complicated. Paranoia and doubt have reached critical mass in our collective consciousness, so we must begin discussions around maintaining the faith in and trust of the integrity of our elections.
Democracy creates opportunity. The opportunity is that, we, as citizens of America (or insert your country here if you live in any democracy), believe we have a say in our nation's future. And the definition of democracy, as dictionary.com informs us, is “a form of government in which the supreme power is vested in the people and exercised directly by them or by their elected agents under a free electoral system.” The keys here, are “vested in the people” and “free electoral system.”
If digital voting machines are used, and those machines are manipulated, then it's no longer a “free electoral system,” and not really “vested in the people.” The power then starts to shift to the “cyber few.” The more troubling aspect is that the outcome doesn't have to be changed; there just has to be doubt as to whether or not manipulation occurred. And in that sense, some are already saying the hackers have won.
The reason why Election Day should be a little more resilient to tampering (at least in the cyber sense) and result in a fair outcome is because of diversity. Much like a stock portfolio, the diversity of our states and their voting precincts means the risks are distributed and in some ways mitigated.
Because there are various types of voting machines, and most of those voting machines are not connected to the internet, manipulation on a large scale becomes extraordinarily more difficult (though not impossible). Furthermore, some districts are paper only, and others have a paper-trail. While a paper-trail in and of itself is not perfect, there's the comfort that it's more than just a few bytes of computer memory that provides the actual vote tallies.
We have to be diligent and cautious, though, because there's still risk. One major factor is that our presidential races, and even some of the senate and congressional seats, can be extremely close. It's like saying despite having a diversified stock portfolio; one stock can actually determine if you are rich or go bankrupt. So, in the election sense, if a single state's voting machines can be manipulated, that could be enough to swing the election. Or, as mentioned earlier, it might not be about swinging an election, but merely to cast doubt. This scenario is much more possible.