Anonymity is hardly the best way to commit journalism.
Too many anonymous sources crowd into basic reporting. Too many such sources take free swings at those they oppose. Too many journalism organizations permit such unattributed criticism because it makes for salty, lively and descriptive reportage.
It's interesting to see Google take a slightly different stand in its Wikipedia rival, Knol: Only identified authors need contribute. I had a closer look this weekend, and it has enormous potential to add to the digital sphere.
Now, I happen to love Wikipedia, but I also know it is susceptible to rogues in the wide community of scribes. For some it's a reasonable price to pay for the general good --- and speed and scope --- that comes with the wiki. I'm not so sure anonymity is necessary for something like a reference work. I stop short of citing Wikipedia, as do my colleagues, because they are concerned that recent posts have been massaged. It's far better to know the Knol writer.