Apple has released iPhone firmware version 1.1.4. Though anticipated by many, the release of the new firmware has not coincided with the release of the iPhone SDK. Instead, the apparent reason for the release of the new firmware is to resolve bugs caused by or left lingering after the release of iPhone firmware 1.1.3.
As always the new firmware is available for upgrade through iTunes, or via direct download from Apple. Users upgrading via either method should always make sure their iPhones are backed up before beginning the upgrade process.
Apple's release notes only indicate that the release includes bugfixes, while not stating specifically what these fixes are. Early indications are that these fixes are related to Bluetooth issues caused by firmware 1.1.3. Forum discussions popping up around the web also suggest that the new firmware fixes issues with SMS ordering that were introduced with 1.1.3.Check back frequently for updates to the list of fixes included in 1.1.4.