Personally, I think "don't have a newsletter" is a great idea (it reduces UI cutter too), but people want to send newsletters and the only way to make sending a newsletter worth the time spent to prepare it is by making it opt-out not opt-in.
edit: I'm not saying I support this, just that a newsletter is never done in the users' interest but as an advertizement. It might make for good UX for the user for it to be unchecked, but thats kind of the point, the entire concept of the newsletter relies on bad UX to gain subscribers.