In the preface to his 2008 book, He Is Not Silent: Preaching in a Postmodern World, Al Mohler lists six reasons why preaching has been undermined in the contemporary church and is weakened at this point in time. Let me list the reasons with brief explanation:
1. Contemporary preaching suffers from a loss of confidence in the power of the word. People today are bombarded by more words than ever before. Words have become very cheap and are increasingly replaced by the use of images or sound tracks. Generally people have lost confidence in the power of the spoken word, any spoken word.
2. Contemporary preaching suffers from an infatuation with technology. Well intentioned moves to incorporate visual media technology have inadvertently changed the core shape of the message – a message intended to be heard rather than seen.
3. Contemporary preaching suffers from embarrassment before the text. With the ongoing and repeated attacks on the biblical text from all sides, not least the current politically correct climate, many preachers are hesitant to preach the whole Bible since some parts are so offensive to contemporary sensitivities. Consequently many stick to the more comfortable, palatable and non-confrontational passages, while shuffling nervously around the rest.
Tomorrow I will finish the list.
Biblical Preaching 
Mohler is absolutely right. In addition many post-modern preachers do not have a burning message to proclaim or a motivation to preach, except that it is Sunday and it is expected.
http://www.preachwithpower.org
While I agree with the first and third statement as being true for some, I totally disagree with the 2nd. The message was intended to be communicated. Jesus often used visual means to communicate via natural illustrations like seed, fig trees, mustard seeds, fish, etc. What I do as a preacher who uses visual media in my sermons is akin to parables. I use real world illustrations. Secondly Jesus used stories to teach. As a preacher who uses visual media I show stories. Instead, visual preachers who use story are communicating more like Christ than a preacher who merely uses words. Both can and will be used of the Holy Spirit effectively so long as they are faithful to the meaning of tone of the text.