Good question, and this should be counted also for some other other activities too (like, you can't do instanced quests while you queue: not the biggest issue but it would definitely be a nice addition).

I swear I always forget that I can use my chocobo, since that I constantly queue for dungeons and pvp and while I do so I can't bring him out for anything relevant, rendering him useless for me (keyword here being: for me. I'm sure others don't queue as much as I do).

I don't know anyway, I suppose we'll get this fixed in 4.0. Maybe!