And this slight update is said not to be containing the major changes, instead it's meant to be a preparation for the upcoming round of international launch. Because the iPhone sale in the world-wide would be bundled with iOS 5.0 firmware, and people who buy the device and decide to update their software would receive this tweaked version update.
If you are planning to upgrade to this release, then follow the below direct link then:
Download iOS 5.0.1 (9A406) firmware for iPhone 4S
Or you can view our iOS firmware download archive page.