Many people think that Public Relations and Journalism are pretty much the same thing. There is the assumption that if you are a journalist, you can work in PR, but this is not true. While PR and journalism are the same, they are also different.
Public Relations and journalism have a mutual relationship, meaning that PR needs the press and the press needs PR. Journalists rely on PR for stories, because many times they go to PR professionals to get the information they need to write a story. PR professionals rely on journalist in return to write a good story about an organization, person, or event. They rely on journalists also because journalism is one of the biggest media outlets out there. Both are hesitant with each other because they have to trust one another to give accurate information.
I think this video: http://www.youtube.com/watch?v=8CbiMXV8U4M&feature=player_embedded offers a good look at the relationship between PR and journalism.
I think the reliance of PR is getting smaller, though has not been eliminated yet, due to newspapers dying off. Newspapers are not as popular as they use to be so PR professionals are having to rely on other forms of media and such to relay their messages and stories. PR is turning to social media networks such as Twitter and Facebook. These social media sights are popular today but one day these too will die off and PR will have to look at another way to spread their word.