Arduino 0022 has just been released. I recommend downloading it and then deleting the old one (be sure to move any of your sketches over the new folder). This new version has a library for talking to SD cards as well as a few new functions for character manipulation macros. It also has patches that solve some of the issues you may come across if you don't update. You will not need to update your drivers.
You can download it here: http://arduino.cc/en/Main/Software