Digital media producers and managers need to know HTML but don't necessarily need to know Flash. And the intangible talents and skills that journalists needed in the ancient world of newspapers, radio and television are the same in the digital world.
These are some of the inferences that can be drawn from a study by C. Max Magee of skills used and needed by digital journalists every day. You can get a PDF of the full study here.
Since online journalists spend a lot of their time repurposing material from one medium to another, copy editing skills are more important than they might be in a traditional newsroom. As might be expected, those who work at larger organizations put a bigger emphasis on editing rather than reporting and creating original material. At smaller sites unaffiliated with a major news organization, the opposite is true.
Magee based the study on responses from 438 journalists, with more than half the responses generated from members of the Online News Association.
HTML, use of content management systems and Photoshop were the three most highly rated skills.
Be sure to have a look at the color-coded charts at the end of the study which rank all 35 skills and talents measured.
There are other articles and surveys on the topic referenced in this piece published by the Project for Excellence in Journalism.