in patch 3.1 and before pallies found out they could stack so much int, and nothing else, that with crit regen and replen, and dp, they could cast HL non stop on almost all boss fights in game at the time. They stopped worrying about haste/crit, or any other spell like shock/fl and so on. beacon wasn't even imporatant, 90% of the time u put it on yourself to keep alive, or on ot on heavy tank damage fights (patch and so on)
bliz saw this trend and did not like it. sure u can gear well rounded, and keep tank alive without chain casting HL, but why bother when u can just use one button on tank mashing the button over and over and be a "pro" tank healer. Never showed up on evective healing meters, because that's not what pallies really do, but they keep tank, hence the raid, alive. druids/priests/shammies did the rest.
now, they nerf regen big time, and they nerf our int and add in 100% heals on beacon, instead of effective. u wouldn't think that would change things so much. but it did. now there is even more of a push for int and regen gear. because now u can accutally put that HL spam to good use while tank healing. it matters. U can beacon your tank,and if u can manage to hl spam on hard mode 25 mans, it is crazy. i was in the 4.1k effective heal range on xt hard mode tonight 25 man. for the whole night (4 real bosses, 1 hard mode) i was 1 i effective heals at 2.9k hps.
i don't think blizzard will like what they created. no lie, pallies are one of the most powerfull healers in raids right now. and i know blizz doesn't want them that high up.
my guess is they'll cut the mana u get back from dp by 50%.