Why would I need a new driver?
New drivers are created for a number of reasons. The most common reasons are to implement features that may have not been technically possible before or to correct a conflict that may be occurring between the driver and other hardware or software in your computer. Imagine a new program that speaks French, but your drivers can only translate English, German, and maybe a little French. A new driver to correct the conflict might know a lot more French, along with English and German. New features are often added with new drivers, as well. A new driver for your video card might allow it to more efficiently draw three-dimensional shapes or add dynamic lights and shadows to your favorite game.
Having the most current drivers is usually a safe bet, however, if you are not experiencing any issues or do not really want the new features the drivers may add, you probably do not need to download anything. For the most part, having the current drivers will improve performance. In rare instances though, a new driver may cause a conflict that you were not experiencing before.