Hi,
I tried to solo Sapphiron-10 recently as shadow and, by the lack of skill/gear/luck/whatever I can't down him. I'm running oom very fast because I need to heal a lot. Thus, the idea is to try this fight as Disc!
The enrage timer is rather easy, 15 min, so the average DPS required is below 5k (4648.3 to be precise), which is doable for a 385+ geared priest. The sheer amount of atonement healing (essentially, ~50% of our dps) will help a lot.
I tried to make a disc-solo spec, along the lines of
http://www.wowhead.com/talent#bfrzMRcbcRrobuMZb:qomdaq
Note the usage of Renew, it is inefficient mana-wise, but casting it doesn't suffer from pushback.
Btw, I tried to solo first boss in TotT normal (Love in the Air charms farming, lol), standard disc spec works like a charm.
What do you think? What should I change?