scroll down on this page from xbox.com to see the full list that the new update will do....it does lots of stuff
'You may not even notice all the new features, but they are all designed to enhance your Xbox Live experience. Some of the other features in this upgrade include:
-The name of game in tray is now displayed in the dashboard.
-When the tray icon is highlighted, a list of achievements, game icon and gamerscore for that game is displayed.
-Video trick modes are enabled for content that is being progressively downloaded from Video Marketplace.
-Playback progress bar indicates download completion.
-Improved skip forward, skip back functionality during video playback.
-Switchable aspect ratio now available during video playback (Auto to Letterbox, Zoom, Stretch, Native).
-Player and friends lists now quickly show session presence information for quick identification of users that are joinable.
-Support for streaming WM-DRM protected content from a PC
-Folder view for video content on connected devices
-H.264 video support: Up to 15 Mbps, Baseline, Main, and High (up to level 4.1) Profiles with 2 channel AAC LC and Main Profiles.
-Added MPEG-4 Part 2 video support: Up to 8 Mbps, Simple Profile with 2 channel AAC LC and Main Profiles.
-Show folder hierarchy for video content played from all devices.
-Bookmarks are stored for each video that the user plays remembering the users last location in the file as well as the aspect ratio that the user choose for that file.
-Video trick modes (fast forward, rewind, chapter skip) can now be used while downloading Video Marketplace content.
-Skip forward and backward functionality has been improved to skip to the next or previous chapter. Each video is divided into 10 “chapters” allowing you to quickly skip around video content.
-The information bar that is turned on via the On Screen Display (OSD) now shows you exactly where you are in the playback of the video file. In addition it will also show for Video Marketplace content how much of the file has been downloaded and where the “chapters” exist in the file.
-Windows Media protected content (WM-DRM) can now be streamed from the PC to the console. If the WM-DRM license is missing or corrupted then a specific error message is displayed to the user. Bookmarking is also stored for protected content.
-When the user is in the dashboard and an Xbox 360 game is in the console then the name of the game is displayed in the tray icon of the dashboard. If the user highlights the tray icon then achievements and gamer score are displayed for that game based on the signed in user. Xbox1 games show the name and image of the game.
-Bookmarks are stored for each video that the user plays. The user can delete all bookmarks but this will reset all bookmark information for every video that the user has played. The bookmark database is exposed in the system/memory/system items
-When a user selects an item for download from Marketplace then the system will determine if there is sufficient disk space for the item and, if not, will ask the user to delete content on the HDD. The system provides a sorted by size list of videos, game trailers, demos and arcade content to aid the user in the deletion process. The same list of items are also available from within memory so that users can quickly see which items are consuming the most disk space.
-The console will block the user who attempts to download content onto a storage device that will never have the capacity to store the item without deducting any points associated with the content item.
-The screensaver is disabled when playing photos from any source'
there is also rumour that they are indeed working on group chat(hopefully not seperate channels)...but unlikely to see the spring update