The article mentions that they use them for aerospace components, including landing gear. I wonder what the strength of these parts are compared to traditional manufacturing techniques. Can these parts be used for actual structural elements?
First, metal is a LOT heavier to throw around than plastic. So, your control systems have to be dramatically bigger.
Second, the melting points of metals are way higher than plastic, so the energy required to be right at a critical point of flow/melt is a lot bigger. Not to mention the percentage difference between melted and not melted is a lot smaller.
Third, a lot of the metal techniques are about melting metal in place. That means that the part is buried in a block of powdered metal. That block of powdered metal is a significant fraction of the weight and cost of a plain old hunk of whatever the metal is. Try imagining fabricating even a small gold part out of a powdered block of 6"x6"x6" of gold--now think about how many metals are WAY more expensive than that.
Finally, powdered metal is explosive. Most machines working with powdered metal require nitrogen atmosphere pump down and if there is a leak ... KABOOM.
A good example of part-strength is the 1911 Solid Concepts in Austin printed late last year[0]. They used a EOSINT M 270, a pretty advanced and expensive SLS printer. [1]
For reference, that 1911 ran about $600k in build cost. yeesh.
[0] - http://www.thetruthaboutguns.com/2013/12/robert-farago/gun-r... [1] - http://gpiprototype.com/services/eosintm270.html