Here is a list of changes:
General Fixes/tweaks
Windows Vista: Mouse cursor should no longer have an offset in the menu.
Windows Vista: Unrequested launches in windowed mode should occur less often now.
Timedemo can now be started from the command line.
Better dynamic texture support for enthusiast mode.
New Features
Added 64-bit executables for Windows XP x64 and Windows Vista 64-bit version. In Windows XP x64 a new shortcut will be placed under the Crysis Warhead program group. In Windows Vista right-click the Crysis Warhead icon in Game Explorer and choose to run the game in 64-bit mode.
Known Issues
Games saved in 32-bit won’t work properly when running the 64-bit version and vice-versa.
Note: After applying the patch the version displayed (lower right corner of menu) is 1.1.1.710.
No release date for the patch was given.