I love the idea. It is very "purple cow" (great marketing book by Seth Godin). You should do it alone - the craziness is the amaziness (lame attempt at a catchy rhyme). 1M posts by 50 people or the like is already being done - that`s called an active blog.
It is the story behind the blog, that makes it unique. I suggest the preparation you do is PR. Have your press releases ready, have the numbers of local news and local papers ready, etc. The second you get rolling, start the PR campaign. If you get good PR, your value will increase. The final spot may be worth $50,000 or more - if you have GREAT PR.