No journalistic experience here, but I have an opinion
Sounds like a great idea but a huge time committment. To give the articles enough meat you would be committing yourself to hours of typing and researching every day. You have to love the work or it could get old real fast. Although once it started becoming more popular, you always could hire writers and add columns from others.
I imagine for the first couple of weeks you would need to give away most if not all your work to get people familiar with the newsletter before they plunk down cash for it. You might also get good publicity from local media-Tv and radio if you issue press releases. Also it would make sense to keep it more or less politically neutral, at least from the start to avoid alienating a segment of the population. I also think it needs a certain "edginess" to it, not found in the mass media- I think that would be appealing for its difference.
Well, just some thoughts, good luck- send me a copy if you decide to do it!