Me as Holy and a Paladin heal most of ICC
We have our Kitty Druid go Resto for a few fights tho - Dreamwalker (As holy is terrible at this plus I am renew spec so I am even worse due to taking no single target healing talents) and Sindragosa.
Bloody Princes is hard but do-able, Same for Queen.
I am thinking of changing my spec for 10 mans to a more cookie cutter build tho - I am using flash heal in there more than I ever have!
We have not downed Lich King yet tho - At the moment we are atempting it with Me as Disc, Holy Paladin and Resto Druid