There are no new features yet. It is just a preparation for future updates.
Source: http://majornelson.com/archive/2009/09/23/xbox-360-system-update-rolling-out-no-new-feature.aspx
It prepared the xbox for the New Xbox Experience that is releasing later this year.
Between August and September by the looks of it
Between September 10 and agugust 15
It is coming out either in late September or early October.
It is due to come out near the end of September 2012.
No games will update your Xbox 360. When you insert a game and it asks you to update, this is a game update.
Firstly, get your network status on the Xbox 360 network settings. This will tell you if connected or not etc. If you know its the update, you can go onto the xbox website and download the update manually. There will be a installation guide to apply the update.
Games releised after the update's reliese should carry the update. You can also get the update through Xbox Live.
They are finally doing an update on the system and xbox live. New features, new avatars. It will be off for 24 hours on the 29th of September.
Yes you have to have Xbox live to update your flash drive.
Connect your xbox to the internet, sign in to your xbox live account. Launch the game and if your using an old version the game will automatically update. You will be prompted to confirm the update.
Aug 23 xbox live september 22 for ps3