I recently read an article at The Consortium that advocated having a dual-gathering (mining/herbalist) character, especially at the start of an expansion. Since I was already shuffling professions around on my characters, I figured that I'd shift Aeven from being a miner/skinner to a miner/herbalist. How long could it take, really? Besides - I'd actually be making some money in the process, which is different from leveling a crafting profession. So, why not?
Four hours later, she's now at 475 skill in herbalism, and already able to start picking nodes in Cataclysm content. Running through Hyjal was fun - it seems like she was running into a node (Cinderbloom, Stormvine or Obsidium) once a minute or so, and her bags started to fill up pretty quickly.
If Aeven is going to become my main gathering character, I'm not sure what I'll do with Aretae. Having him as an herbalist seems redundant, but I'm not sure it's really worth it to train him as a leather worker or a smith.
In any case, I'm pretty sure that for MoP, I'll end up rolling and leveling a female Pandaren monk. Take a look at that link, there. She's so FLUFFY! Ahem. That's another two primary profession slots to look at - perhaps I'll level skinning/leatherworking on Aelin, and blacksmithing on Aretae? Hmm. Decisions, decisions.