Update season for Nokia mobiles :) , recently Nokia updated 5800, 5530 and a performance update for Symbian^3 phones. The Nokia X7 got new Anna firmware update v025.007. Many new features, total increase in system performance, fixed several bugs and brings out the latest features.
The update is currently rolled out for U.S ans Europe versions and will out for the rest of world soon.The update is currently downloaded via OTA (Over-The-Air), or via the software NSU (Nokia Software Updater).
No official changelog yet but user which installed this update, The Nokia X7  has the option  of UDP (User Data Preservation), so as not remove any data during the upgrade. But you should back up your data before update to avoid any problem.