I was kind of expecting this but it's sad to see them go. Lets just say it's not my first time at this rodeo. I would advise those afflicted not to sell/discard your painted miniatures, I did that myself and regret it to this day.
Also, you will be surprised how player communities can keep a game alive. If 4th edition sucks, your mates will gladly go back to 3rd. As for tournaments, from what I saw from TOW, I don't think most independent TO's will be banning any of these armies.