Juan Varela has a first examination of the impact of the citizen journalism — pictures and words — on coverage of the Valencia metro disaster on the Periodistas 21 site. It is in Spanish but there is a summary in English at The Editors Weblog.
Varela draws the distinction between information that aids understanding and that which feeds morbid visions and says the flood of information presents new challenges to journalists. There are dangers that so much information creates confusing noise and that conspiracy theories can be spread rapidly through forums and blogs.
Well worth reading.