I also spoke to a CS agent today - she said emails started going out over the weekend and to expect the next promo email by Sunday.
Like others have mentioned she said subsequent stays after the 2 stay promo but before the next stage registration will not count. She did seem surprised that there was this change in policy over prior promos.
While the second stage will be member-specific (and thus she couldn't tell me what my second promo would be), she did say it is a points-per-stay promo.