Holy paladins have come a long way since our days in vanilla WoW. Back then, we were a three button class: Cleanse, Flash of Light, Holy Light. The infamous addon Decursive even did all the dispelling for us, leave the human user simply casting Flash or HL for hours on end. Seals and Judgments were for retribution and protection: we were standing 40 yards away filling up life bars. Things didn't improve much in TBC either: while Holy Shock was fun to finally use, we ended up being purely FoL bots in most raid situations.
Blizzard took a new approach to healing in Wrath, including completely revamping each existing healing tree to make sure each one was balanced, viable, and most importantly, enjoyable. Holy paladins now enjoy a complexity that is multiple times more entertaining to play than anything that we've seen in the past. However, with this added functionality comes added complexity. To help us lighten the load, we can use a few amazing addons and macros manage our "holy 3.0" paladins; this allows us to focus on keeping people alive.