Personally i think that if blizzard wants us to stop using bubbles to blanket the raid i think that they should leave bubble the way it is now (i LOVE it the way it is now) I think that they should make it so that you can only have 3 bubbles on the raid at one times, so if u are a tank healer (which i am) you can bubble the two tanks and then have one left over for a raid member. I think that that would be the optimal think to do, dont decrease the time that we have for them to be consumed (because 1. that will prevent us from using them at the start and 2. the chance for a rapture to proc will be decreased in some fights).