The update is about 10 minutes long and there are three separate updates.
1. When you first sign-out
2. When you sign-in
3. After Xbox restarts
The update contains no new information but is the start of updates for more updates that will change the appearance of Xbox.
"There are no new features that will show up once your system has been updated. This update is preparation for additional system enhancements coming to Xbox 360 later this year."
Source: Major Nelsons Blog
1. When you first sign-out
2. When you sign-in
3. After Xbox restarts
The update contains no new information but is the start of updates for more updates that will change the appearance of Xbox.
"There are no new features that will show up once your system has been updated. This update is preparation for additional system enhancements coming to Xbox 360 later this year."
Source: Major Nelsons Blog