We lost 4.... but I think they were losing interest after 3+ years anyway, the changes in game just acted as the catalyst. Participation in chat rooms - or lack of - told me they were heading in that direction months ago.
We had no problem filling back up with hungry and enthusiastic members at the 200M GP range. I think a guild or three packed it in and the refugees have bolstered the guilds that stayed focus. Those sorts of shifts are necessary and sometimes need a push to get going too.