The browning, known as the Maillard reaction, is a very important to flavor and appearance.
The browning causes a chemical change at the surface of the meat that creates new flavors that would otherwise be absent. In addition to browning the meat, it is key to include the brown bits stuck to the pan (fond) in the recipe. If you brown the meat in the pot you where you will be doing the remainder of the cooking, you're all set. If you brown in a separate vessel, deglaze the pan by adding a little of the cooking liquid to be used in the remainder of the cooking to the hot pan and scraping the bottom to dissolve the fond. Add this to the main dish.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan