This morning
AT&T and Samsung released an update to the Galaxy S II. Containing a few minor bug fixes and updating your OS version from 2.3.4 to 2.3.6. The update started off in good faith that all was right in the world, but many people had issues installing the 20MB update. If you ere one of those many, there is already news out that they are fixing that issue and re-releasing the update again.
As with all updates, this might take a few weeks to hit every Galaxy S II in the wild, so be a little patient. You can always head into your device settings  > about phone and see if it is waiting for you.
Happy updating.
Source: AndroidCentral
