Enchant system in reaper of souls is still under testing readjustment by development team, said Wyatt Cheng in an interview not long ago. He discussed the value of enchanting with players, and tried to let them know the design purpose exactly even the system becomes differently from today. Among the values Wyatt mentioned, which option is the one you care?

Actual Hunting Support. Now the system is set to craft only one property of the item, so it won't get too far from the original one. Players have more chances to farm better items to enchant, thus making the game meaningful to enjoy.

Item Consume Method. This goal is planed to work at later stage of the game. According to known information, enchanted items will become account bound. Though only one property is allowed to craft each time, you can reroll over and over to get the one you want. Legendary items are available to do so in the future to make enchant system the item consume method. For the possibility of enchanting inherent property or only random property, that is still undertermined. 

Avoid Buyer's Remorse. There are big chances that your items may turn worse because the enchanted property is absolutely random. To avoid this awkward question, diablo3 enchant system has a new property list, in which there must be one before enchanting. In case you are not satisfied with new properties, you can pick the first one at any time.