Biggest change (albeit rather minor in the grand scheme of things) are mobile device detection and options regarding the search bar focus
Mobile Device detection *slightly* adjusts how the system works when running on a mobile device (currently how the resizing works when rotating, and the setting regarding search bar focus). Since the distinction between a mobile device and a computer can get rather blurred nowadays, the there is an option (below) to force on/off/auto the only change that this really affects for the end user.
Search Bar Focus Previous behaviour was to have the search bar only in focus when entering the Apps tab, so you could immediately search without having to click in the bar. A new option is available in CA settings to allow you to adjust how the focus works:
Automatic (default) - This keeps the search bar always in focus at all times so that no matter what you've done or clicked, you can always start banging away on the keyboard to have it begin to search. Automatic means that this feature is enabled from a desktop / laptop, but disabled on a mobile device (Some mobile devices do not like this and will continually scroll back to the top of the page when using CA)
Always in focus - This forces the search bar to always be in focus. As stated, some mobile devices may have trouble with this.
Never in focus - This is the previous behaviour, where the search bar is only in focus on the initial load of the Apps tab, and after clicking anything you will have to click into the search bar to type.
Beyond that, some optimizations and fixes that nobody has noticed which means that either no-one uses CA or I'm just anal on this plug.