Switching from Ret to Prot @ 75

[Slaytanicus]

Should I quest in my tanking gear or dps gear?

[Offhand]

Basically just stack strength like all hell. If you have BV trinkets from level 70 use them.

You will enjoy ShoR. The first few times it crits you'll feel like a dps.

[Slaytanicus]

What would a good prot leveling spec look like @ lvl 75? I'm guessing Reckoning would be good for leveling.

[Abstract]

I just did this, and it is great. I leveled as ret to 75, and decided I'd spec prot, cause of the lack of tanks on my server. Check up Abstract on Ahn'Qiraj (EU) if you want to check my spec. Also, read up on www.maintankadin.failsafedesign.com to find out how to play it, how to gear, and different specs.
You will find that your rotation will be slightly more advanced, but you'll get used to it.
As for questing, I quest with my regular tanking gear, and I only use 3-4 more seconds on single pulls, and it goes a lot faster when you pull multiple mobs. And also, remember Divine Plea is your friend!

Edit: Changed maintankadin url