Can you spawn special villagers?

In minecraft 1.3.1, the different types of villagers are now important as they trade different things. However, not all types will necessarily spawn at once. If I occupy a village that lacks, say, a blacksmith, can I encourage one to spawn, perhaps by building a forge?

Just build more houses of the normal type until you get a blacksmith. The profession of a new child is random, and independent of its parents' professions.

you can use this:

/summon Villager ~ ~ ~ {Offers:{Recipes:[{maxUses:#,buy:{id:#,Count:#,Damage:#},buyB:{id:#,Count:#,Damage:#},sell:{id:#,Count:#,Damage:#}}]}}