Microsoft has just released the January 2006 System Update for Xbox 360, highlighted by improvements to the Xbox Guide. Here are the details:

We’ve been listening to what the community has been telling us, so we’re happy to announce that this update will improve your gaming experience.

Here are some of the changes in this update:

Improvements to the Xbox Guide.
Option to retain your saved games when you delete a profile.
Increased accuracy of “last time played.”
Network configuration improvements for Xbox Live members in the Netherlands.
More detailed messaging for unreadable disk or region errors.
This free update is available to all Xbox Live members. Your console will be updated the next time you sign in to Xbox Live.

Boot up your 360 to grab the update.