I do not have any particular expertise in the inner workings of the Wall Street Journal newsroom, but this chart speaks for itself. It shows the number of stories the Journal published that were over 2,500 words from 2002 to 2011. Dean Starkman of Columbia Journalism Review created the chart and referenced it again today. (He used to work at the publication.)
The Journal is not alone in this trend at the big papers, as CJR has also shown, but its numbers are the most startling.
First, the caveats. Of course, story length is not the only indicator of quality journalism. Second, some of the stories that got shorter might have gotten better in the process. Third, the newsroom at the Journal is obviously filled with strong writers and editors.
Or as the WSJ responded when Starkman first published the chart:
The number of words in an article has never been the barometer by which the quality of a publication or its value to readers should be measured. Every article is reported with unique facts and anecdotes that are needed to best tell the story. We consider those factors, while respecting our readers' busy lives, when determining the length of an article. Our very strong circulation numbers suggest that readers think we're doing a good job.
All that said, the editors in 2002 were not idiots. If they thought there were 200 stories worth running at that length, it stands to reason that many of the 2011 stories were not better shorter. At least some longer, deeper, and more complex stories are either being shortened or left out entirely.