Thanks to Debbie Weil for pointing me to MarketingSherpa's 2006 Marketing Wisdom report-- stories from the front and lessons learned from real life test campaigns. (On the same page, you can also download "ancient" wisdom... from 2005, 2004 and 2003.)
On page 1, the publishers ask not to edit or cut pieces to pass along. So I'll just tell you not to skip the introductory letter from Anne Holland, president of MarketingSherpa. She points out three important trends in 2005.
Trend #1 is a reminder (and wake-up call) for all copywriters and the people who hire them.