Not sure about active witnesses, but I know not all are Disfellowshiped or Disassociated either. I will be at the march, and it starts at 2pm. As far as how long it will last---I am not sure. I was at the press conference in Minnesota, and it was only to last 15min----which turned into an hour. It all depends on the press and the responce we get from the headquarters. Why don't you come and then leave when you have to---to go to work. That way you can at least be there and see what is going on with your own eyes. It will be a day to remember and a very empowering (sp?) day too.
Jes