Go affliction and use Dark Pact.
please warlocks remenber healers are humans too and can make mistakes don't life tap that much in 10man
sunshine avatar is so awesome *w*!.... <3
(Sig too large)
best thing i found was to start tapping just before p3 hits and tap away andy excess HP that you have and then during phase 3 tap when you are topped up due to having penetrating cold and also set a macro up to /w one of the healers saying that your oom and need a heal then as soon as they hela you just tap it away again.
If you have a resto druid this works great