I thought this post from EJ by Rijndael on the Resto design for Cata was excellent, enough that I’m quoting it in its entirety here.
Blizzard is moving towards healer homogenization. As Ghostcrawler said, they are trying to walk a fine between keeping class identity distinct, and having raids be called because wrong healer classes are online. Right now healers are not homogenized enough — paladins are too good on tanks and not good enough on raid, disc are too good on LK, druids are not good enough on LK, etc.
It seems pretty clear to me that Nature’s Bounty + Efflorescence is broken and will change in some way. What’s interesting though, is what the designer intent is.
I think the designers are intending to nerf Rejuv and boost Regrowth so Rejuv will only be worth casting when you move, and Regrowth will be cast when you stand still. This accomplishes a few things:
(a) Diversifies the spells druids actually will use
(b) Forces druids to stand still more. This may seem bad, but Blizzard has been pretty consistent in making the movement/burst/cooldown tradeoff. In other words, a healing spell always has one of three disadvantages: it either forces you to stand still, or it heals over time, or has a cooldown. In encouraging druids to use a cast time spell, Blizzard is freeing themselves to buff druid burst, which is what we need to be a more well rounded healer. I suspect druids in Cata will be more like priests — good when forced to move but optimal when standing still.
(c) Make druids think about where they cast, rather than spam. This is the intent behind Nature’s Bounty interaction with Regrowth, and I think this idea is sound as long as they “smooth” it, and just give a bonus that scales with lower target hp.
I think this is absolutely true. Right now, Rejuv is our most used spell because its cheap, instant, heals fast (first tick in ~2s with GoRR) and heals hard (3kish per tick for a well-geared tree, pre-ICC buff, which is 10-15% of a DPS’ers health pool), and heals over time. It’s too powerful. I think they’ll make it significantly weaker and buff Regrowth, forcing a choice between the two.