I'm friends with BR3AKR, and it was basically us and two of our other friends. There does not seem to be much of a Mage Wars community around here.
Another part of the problem is that the shop we were at closes at 10 during the week, and due to work schedules most of us can't get there until around 7-8. With set up, play, and clean up, there's really only time for one match unless you play quickly (we're still new so it goes slow).
I think we're planning on keeping at it for a while, though we may move the days around if we can find something more suitable. I don't know how much interest we can expect to gain from people just milling about in the shop. I think it's going to stay sort of informal for a while, I don't know about starting a "league" but if we got enough people we could certainly set up some kind of ladder or stats system. I don't have much experience with organized play for stuff like this.