I would like to take this opportunity to disagree with my own post the other day declaring Divine Providence worthless. I was so moved by all your comments that I specced 14/47/0 and took Circle of Healing for a spin through half of Tempest Keep and all of Zul'Aman, and have changed my mind entirely. Circle of Healing is amazing, and I never want to let it go. If Blizzard wants to give me a talent to buff it and other heals by 10%, and lower the cooldown on Prayer of Mending, they can go right ahead.
As you all had predicted out, my estimate of Greater Heal and Flash Heal covering 70% of my healing between them was woefully inaccurate. In fact, in both instances, CoH alone accounted for 70% or more of my healing. The new Divine Providence is +10% to all multi-target heals, and 3 seconds off Prayer of Mending's cooldown (with 5 points in the talent). Even if I ignore the other effects and just look at the boost to CoH, I get (70% * 2%) = 1.4% increase to my healing per talent point, well above the 1%-per-point benchmark.
All that said, I still don't think this talent compares favorably to Spiritual Healing, which is several tiers earlier in the tree. Spiritual Healing simply bumps up all your healing by 2/4/6/8/10%. It's really an amazing talent, and to be fair, it would be hard to match, given that it's far over Blizz's stated budget for a talent point (1%).
If they did want to match it, they could make Divine Providence +3/6/9/12/15% to multi-target heals, which would come out to 2.1% benefit per point (again, focusing on CoH only), but that might honestly be a bit overpowered, especially taking other heals (like Prayer of Mending) into account. My suggestion (borrowed from a commenter on my other post) would be to increase the reduction of PoM's cooldown, bringing it to 5 seconds, but it's not that bad as it is now. I couldn't fit it into my current build at level 70, but I will almost certainly be taking it at 80.