@ash: This is all me talking out of my ass theory crafting, so take what you will of this, but here's what I'd do if I was trying to improve your Dragon Priest deck.
I don't think Priest will get good at dragons until the last wing opens. When that happens though, I'd revisit this deck with the following changes:
-Ditch the old Priest tricks and beef up the dragon-y-ness. I would try subbing out both CoHs, both Auchenai and both Injured Blademasters and try putting in 2 Velen's Chosen, 2 Blackwing Corruptors and 2 Dragonkin Sorcerors. The Dragonkins would help you activate the Blackwings, Whelps, Corruptors and Blackhand more regularly and be great targets for PW:S and Velen's Chosen. If the Sorcerors are underwhelming I'd sub 1 and 1 Velen's Chosen out and bring an Auchenai and a CoH back. The Corruptors are basically a Fire Elemental for 1 mana less, I expect them to be in every Dragon deck regardless of class.
-I'd also think about taking out your Faerie Dragon for a second Northshire Cleric or a Shrinkmeister. Faerie Dragons are usually played before you play cards that need them to activate and they can't be directly healed with your Hero Power or buffed with your spells. Clerics can combo with Chromag, CoH, Velen's Chosen to be pretty effective and Shrinkmeisters can combo with Cabal Shadow Priest or Shadow Madness while still being healed or buffed if necessary.