The Evangelical Christian Publisher's association has announced the finalists for the 2012 cover design awards. Most seem to me ... underwhelming. Some are very bad. There's certainly a clear preference for visual puns and over-literal interpretations.
I'm not an expert at these things. Perhaps the above, for example, does what it's supposed to do in a bookstore, catches attention and communicates a basic idea very succinctly. I can't help but feel, though, that such covers communicate also a deep disrespect for the intended audience.
The very worst of the nominated covers:
Presumably such dreck actually helps sales, though.
Update: A summary of the marketing research behind these designs can be found here.