Home Depot is selling 3D printers for $1400-3000 each. Who’s buying them, and why? What do they print? What about the cartridges? So many questions. So little time! Also, President Obama is trying to stir up some passion for shoring up the national infrastructure. The White House released a report Monday afternoon touting the long-term economic benefits of fixing the nation’s roads and bridges. And Tuesday, he visits Virginia to talk about it again.  But chances are good that his efforts will fall flat.  Even though everybody hates driving on potholed roads, or wants to avoid sewage pipe ruptures, the American public just doesn’t care much about this issue.