Maybe I am late to this particular party, since the experiment has been going on since the end of last year, but I find it pretty fascinating. Ultimately this site will serve as a place to keep tabs on FORTUNE 500 companies that maintain "active public blogs by company employees about the company and/or its products." From the wiki:
Most bloggers, myself included would think (or at least hope) that blog-friendly companies do better in the stock market. "Transparency adds value," and all that jazz, right?"According to our research, 27 (5.4%) of the Fortune 500 are blogging as of 4/4/06
Once we've got this list in pretty good shape, we plan to add share price data to create a Business Blogging Index, comparing the stock performance of companies that blog with those that don't."
Turns out that the blog-friendly companies lag pretty badly. The resulting theory suggests that companies in trouble (GM) are more "bloggy" than those that are on a tear (Apple), because more communication & spectrum-wide conversations are more likely to spur some good storylines... whereas companies that already enjoy a good marketplace storyline don't want to muck it up by introducing new (potentially problematic) perspectives.
This post from Doc Searles' blog explains it all in a far more interesting way via far more intelligent people.