I like the MA a great deal. I don't mean to imply that I don't, and I don't at all want to see it displaced. For special events, the MA is excellent as it provides a place to fly whatever plane you want practice in and to keep your skills sharp. You can jump in whenever you want, and it's an enormous amount of fun. I think a lot of people will continue to fly in the Main Arena regardless of (and to some extent in addition to) whatever other modes of play are available.