Apple released 3.1.2 Update which fixes some of the known issues. Please note that battery issue is not on the list, so if this release fixed your draining battery, let us know.
‚Ä¢ Resolves sporadic issue that may cause iPhone to not wake from sleep
‚Ä¢ Resolves intermittent issue that may interrupt cellular network services until restart
‚Ä¢ Fixes bug that could cause occasional crash during video streaming
In order to get this update connect your iPhone to iTunes and follow standard prompts. Update is approximately 240 MB and available for all iPhone model and iPod touches.
Note: If you have jailbroken phone and you're planing to jailbreak and unlock your iPhone in the future stay away from this update. If you like to know why, because PwnageTool and redsn0w are not yet compatible with 3.1.2