Passive OK in headlines, says Jakob Nielsen's Alertbox. This is sound plain language practice and not new, just a healthy reminder. The first 2-3 words of any headline (or summary) should be words that grab and hold the reader. They won't grab the reader if the active voice is pursued at the expense of focus.
Yes, sentences with active verbs are generally way easier to read than with passive verbs. But the passive has its place, for example, when:
The first example above implies that headlines and titles will often use the passive, especially when they are not complete sentences. And you can see why policy documents will often require quite a heavy use of the passive.
This Alertbox posting amuses me for private reasons. Last year in Sydney I attended workshops on Content Usability, which formed part of Jakob Nielsen's Usability Week. Then, one of John Morkes's inflexible rules for Titles and Headings was "Use active voice". And when I dared to question this rule, I was firmly put in my place.