So uhhhhhh..... Yeah.
I'm not gonna lie, I have no idea what you're supposed to do on this fight. The only thing I do is afk dps the boss. I think there's something about a 4th ooze? Not really sure tbh.
On a serious note, you're going to want to find ooze combinations that benefit from not only your healing set-up, but your dps set-up. We had a raid with lots of AoE potential, and strong healer cooldowns, as well as strong outside cooldowns from the dps and our blood dk 4 piece. Because of these reasons, we chose to go for Red/Black/Yellow phases which are probably the most intense, as it's double aoe damage ON TOP of double add spawns. I was using tricks on different targets based on who was using their cooldowns for each add spawn. (I think we used Berserk swipe, Combustion, Bladestorm/Sweeping Lol, and Infernal) I mean, the fights basically the same except you'll have to deal with purple every once in a while, so it's a steep learning curve for healers. The only thing I suggest is figure out exactly how much dps you need for AoE on the adds and to kill the ooze before it reaches the boss, and try and leave at least one person on boss full time so that you can beat the enrage timer. Oh, and use mana cooldowns when the mana void comes out, that way you can save busting it until another blue phase, and then bust the orb after the new orb spawns for 100% mana goodness TEEEHEEE:DDDD.
As far as my thoughts on the fight go... I feel like Blizzard could have done more with it. It's not a boss limited by mechanics, but limited by pure numbers. It's a heals/dps check in it's core. But it's not badly done, just not wonderfully done.