One of the things that happened to me during MoP that really ticked me off was doing the Celestials weekly for PVP gear. I was on my priest and healing, unfortunately due to doing another activity my loot was set to Shadow. Of course I get legs and they're Shadow. Oops. While it was nice to get legs the first week of that season, it wasn't for the spec I PVP'd in. So I ended up PVP'ing shadow and healing through arena 2's cap in shadow gear until I hit 27k.
Now as we all remember bear tanks for RBG's were mandatory not so recently. Yet they were useless for arena. If you were a druid that wanted to bear tank RBG's you were going to suck wind doing any part of your Conquest cap in 2's throwaway matches when tanking was useless.
Well those were big problems until you hit 27k Conquest and then could buy alt spec gear for honor. How completely worthless.
Now, what do you do with any/all honor while doing randoms for fun, in steamrolling PUGs or with regular RBG friends?
I think the ideal situation to having multiple specs, some very specialized, is offering a Conquest token/slot/unlock.
Example: You get a piece of Conquest gear, legs, glove, helm etc. You have in effect spent 2200 or 1750 Conquest points to unlock that slot. At that point if you spent 2200 Conquest on legs, you can now buy the off set leg item for honor at the same iLvL.
It doesn't make anyone OP or create imbalance. You have a character with 2 pieces of Conquest gear but they're the same slot. It would still take the requisite amount of time to hit the 27k achievement and be fully geared for both specs.
Further with honor caps being an issue if you do a lot of randoms with nothing to buy you can spend honor every week on gear instead of burning it and having to do even more honor farming to buy Conquest gear off spec stuff after you've hit the 27k achievement.
I really think this situation is ideal and would really facilitate people not being pigeon holed in a spec for months at a time until they hit the 27k achievement then still have to honor farm all over again.