Protection is a lot of fun for solo questing. It's not as fast as Ret, but it's pretty good. I used Judgement, Hammer of the Righteous and Holy Shield, and easily went through 1-3 mobs at a time. I didn't feel it was worth using Consecrate for so few mobs. Prot is a little mana-hungry, but I went JoL + SoW, and still killed fairly fast while keeping my health and mana pretty high.
The caveat to this is that I did not use Prot gear. I used my Ret gear + a green 1H hammer from one of the first WotLK quests (~84 dps) + an Illidari Runeshield. When I tried with my epic Prot tanking gear, it just felt terrible. I think you really need a decent amount of strength to make the new Protection work. I'd probably get the new Cobalt blacksmithing gear as soon as possible, and replace all my precious epics.
I think I'm probably going to level as Protection in WotLK. It's solid for soloing, and I can tank instances on the way up.