Villagers should have duel variants. What I mean by that is that a villager's texture should not only be decided by its profession but also by its biome. For example: a priest living in a snow village could spawn wearing a purple fur coat with a white trimmed fuzzy hood. (Like an Eskimo)
In dessert biomes they could spawn with a tattered hood-like cloth that drapes their heads and shoulders, to keep there flawless foreheads from getting sun burn XD.
If villages spawned in more places like a mooshroom island, which many are already asking for but that's a different topic, with villagers spawning in mushroom attire and the librarian in steam punk goggles. (I don't know why but the goggles seam fitting) Similar to the biome settlers skin pack.
Obviously there are a lot of possibilities out there. And I can't name them all at once. Post your biome variant clothing in the comments and I'll add them if they are a good representation of that biome.
Remember to vote of you'd like to see Biome Attire for Villagers added in the Fan update!