Recently, I read a great thread on the official healing forums. Ghostcrawler, the lead systems designer for WoW, posted several times with interesting information and a few explanations regarding the new healing model in Cataclysm. I've talked about the idea of triage healing before, but there were a few specific points that Ghostcrawler made that really resonated with me.
One of the commenters referred to the idea of "auto attack" heals, relating spells like our cheap Holy Light to the automatic attacks of the physical classes. It's a very succinct way to think about it, since we're used to raiding in environments where we never stop casting. It's true, most paladins on the beta have just been spamming Holy Light. I'm guilty of it as well. It almost feels like the old Flash of Light days back in TBC, where FoL was the only spell we used because we'd never run out of mana. Blizzard saw this as a problem, and so the latest Cataclysm beta build contains a major nerf to Holy Light. Ghostcrawler's statement that healers shouldn't be spamming one heal seems almost prescient now.