Healing with druids is easy mode.

DO NOT bother with repeater region micro managed healing with druids - that's for people with bad boxing healers. Make one macro. Make that macro keep hots on your tank and cast wild growth on cooldown. Play with the macro a bit to get the timing down or adjust for mana issues/healing amount issues. Make a few extra macros or use your repeater region stuff for Oh shit moments for your other characters. Bind this all to your dps/tank macro button. Smash that button like a monkey while main playing your tank and paying zero attention to anything else. Congratulations. You can now do every single heroic and 10 man in Wrath.