The days when opportunity came knocking at your door are all but gone. Now, one must seek out opportunity's door and knock on it. It doesn't hurt to come armed with a lock-pick kit and a sledgehammer as back up. The publishing world is changing, not only because times are hard but because of the electronic revolution. It's pretty safe to say it has never been harder to break into publishing. Unfortunately just writing a great novel isn't enough any more. A lot of factors come into play when you're trying to land an agent and sell your novel. The timing and material has to be right. If you wrote an outstanding novel that involves a trend that's on it's way out, agents and publishers will probably pass you by. So they're looking for the next big thing then right? Yes and no.
They're looking for something that has the potential to be outstanding, is fresh and innovative, but that people can relate to. Now you're totally confused aren't you? Don't feel bad, I'm right there with you. Not only does timing have to be right but there is a huge amount of luck that comes into play when you're introducing a new idea or one that's trendy. Voice and style are also a large part of it. You can write a book about a trendy idea but have a completely fresh voice or style that makes it something new.
So what can you do to increase your chances of succeeding in this increasingly discerning and competitive market? Perfect your craft. Take classes, go to retreats or workshops, or read books on the subject, that's your lock-pick kit. While my young adult paranormal series was on submission I've completed another stand alone novel in a different genre. There's the sledgehammer, a positive enduring attitude that won't give up. If you keep writing you increase you chances of success. It's important to keep improving your craft as well. If you can't attend writer's retreats or workshops in person then do so online. If that still isn't an option then pick up books on writing to help you improve.
A vital thing you need to realize is that agents and editors can't define your success if you don't let them. Don't stop improving, don't stop writing, and most important, don't give up. In the end, know your options and weigh them all.