What kinds of issues would you like to see explored in a novel? What kinds of non-fiction topics would you like to see?You're going to get slightly different answers from each publisher. But. . .
Anything that we, as people alive on this planet, have to deal with is a good topic. It's not so much the topic, as the treatment of the topic that often gets books rejected. I think you can find books from LDS publishers that deal with just about everything, although sometimes not as honestly and straightforwardly as some of us might wish.
I'd like to see YA books dealing with peer pressure, living in the real world without succumbing to its negative influences, maintaining hope and faith despite the crushing blows that life can send your way. But they can't be preachy or have simplistic answers, and they can't sound like they were written by an adult as a way to teach the youth how to live a better life.
I'd also like to see some just plain old fun genre books with LDS characters, but no one trying to convert anyone else.