Your customers and social community members know you, like you and trust you. If you're writing a blog, they want to know what you think about what is happening in your industry, in your field. Your blog is your stage to tell them what you really think about what's happening, what trends you see.
Don't be afraid to step up and tell your community what you think. Seth Godin in his book, "Tribes", states, "If you think leadership is only for other people, you're wrong. We need YOU to lead us."
Your tribe is looking for your input on new ideas. Tell them your position. But what if some people disagree? That's good. If they disagree and tell you so, that's great! Now you can interact directly with them and explore both sides of the issue. This is the type of interaction your community wants.
So speak up. Voice your opinion. Engage your community.