The latest firmware from Apple is already here. Just over two weeks after the release of iOS 4.3 for GSM iPhones, Apple has added bug fixes and other minor updates to iOS 4.3.1. The update was made available on iTunes earlier than expected. Verizon iPhones (CDMA) will remain at iOS 4.2.6 for the time being.
This update is also designed for the iPad, iPad 2 and fourth generation iPod touch. Although the update is relatively minor, if you are one of the users affected by issues addressed in the update you'll want to install the new firmware right away.