The Blacksmith is the first of the Artisans you'll meet in your travels. According to the Beta, the NPC will ask for your assistance in a quest (spoilers omitted). Once completed he will join your Caravan and provide you the Salvage Cube.
Here is a run down of the Blacksmith Features and how they may affect you.
1. Salvage or "Nephalem" Cube
This cube will be used to break down items into materials used in crafting and Artisan training. It can also be used a secondary storage unit, similar to that of the Horadric Cube of D2.
How will it affect you?
Salvaging items will be critical as we begin to gain data on probability of rares in breaking down these items for their materials. These materials are used in crafting and training.
2. Crafting
The backbone of the NPC. While the NPC will have standard items he will craft and sell, you will also have the ability to train him in rare item crafting through dropped recipes.
How will it affect you?
If you can corner a market on a recipe, look for large benefits, focus heavily on PVP gear and very early, and late game heightened gear.
3. Reparing
The Blacksmith with repair your armor for you as it degrades, similar to that of D2.
How will it affect you?
Simply put, this is a gold sink. Other than weapons, the less you get hit in the armor the less of a gold sink this will be.
4. Socketing
The NPC will provide Socketing services for armor and weapons. The current speculation is that the items can be of any quality, and that training your artisan can provide additional socketing slots to armor.
How will it affect you?
If this is indeed the case, and socketing an item does not change its level requirement, putting multiple sockets in low level armor could be very lucrative. More on this when we get to Gems.
5. Training
This is how you move your Blacksmith through the 5 lvls of progression and requires materials and gold.
How will it affect you?
Another gold sink, but assume that most will try to level this as quickly as possible. Look for gold and training materials to be the early game high sellers.
As always, look for arbitrage opportunities in these areas.
