The DC Universe has always had its fair share of mad scientists and genius inventors. Despite this, SOE opted to not have crafting in DC Universe Online from launch. Gadgeteers and scientist heroes or villains had to content themselves with purchasing or hunting down their precious mechanical gear. Some players felt that this was a glaring omission and something that should be standard for all MMOs, while others argued that crafting had no place in an action focused game like DCUO.
SOE have been expanding their MMO a lot over the last six months, including making it free-to-play and adding two major premium updates, now they've decided to move onto crafting. Crafting in DCUO has been given the appropriately modern name, Research and Development. They've put a simple explanation up on their site, which should answer some of your questions.
Players will be able to discover residual Exobytes from Braniac's attack -- called Exobits -- scattered all over Metropolis, Gotham and Central City. Along with plans they can be crafted into equipment mods and consumables. Besides constructing new items, players can salvage some gear to gain new components. It's nothing unexpected, but it should add more depth to the game (something it sorely needs) and a more lively player economy. There's no word on the launch date yet, but there will be more information provided on the DCUO webcast tomorrow at 4:30pm Pacific.