Can "Citizen Journalists" do the work of the "Main Stream Media"

Short answer: no
Longer answer: they don't have to

There a great deal of discussion about whether the "blogosphere" (that word makes me hurl) can do the job of uncovering information that the "main stream media" (almost as bad a term) does presently.

Of course not, only a full-time journalist has time to do sustained in-depth research on a subject to report on it fairly. Fortunately, when the blogosphere becomes sufficiently large enough to encompass all manner of topics currently covered by the main stream media, it won't be necessary to find and interview authoritative sources. Instead the authoritative sources will be able to speak on the topics themselves.

For anyone who has seen a topic they are familiar with covered in the news, the intarweb finally creates a back-channel to correct and explain the inumerable partial quotes, mis-quotes, and quotes taken entirely out of context.

The biggest missing pieces to making the p2p media a suitable replacement for the current news structure are:

1) More data (i.e. more people posting and contributing their specific domain knowledge)
This problem should sort itself out as contributing becomes easier and generations that have grown up with the intarweb accumulate knowledge to contribute.

2) Better filters
Google is hard at work on this for web pages, but has hardly dipped its toe into adding reputation scoring to individual authors and comments.