Here is a list of the main changes to come with the new hak update. All these should be tested:
Spell Changes:
-Changed the description of Greater Stoneskin to properly indicate it's an Abjuration spell, not Transmutation.
-Added two new spells: Protection from Curses and Mass Protection from Curses (+4 vs Curses).
-Updated Augment Healing to use the spell level rather than the innate level to calculate how much extra healing is applied.
Feat Changes:
-Added the following feats: Lunatic, Skill Focus (Disguise), Epic Skill Focus (Disguise), Charlatan and Recognize Imposter.
-Made slight revisions to Unorthodox Flurry and Flurry of Blows' descriptions, replaced references to kamas to references to monk weapons.
-Add racial feats for the subraces added recently (Fire Gnome, Frost Dwarf, Axani, Celadrin)
-Made Back to the Wall apply very quickly in combat.
-Updated the prerequisites to Shrouded Dance.
Skill Changes:
-Added the Disguise skill, which will be countered by Spot.
Class Changes & Fixes:
-Changed the way AC is given to Dwarven Defenders so it's base AC instead of "natural" AC, it will now stack with all forms of AC.
-Revised the order in which feats are given to Dwarven Defenders: Uncanny Dodge at level 4 and Improved Uncanny Dodge at level 6.
-Added new metallic wyrmling shapes for shifters.
-Added Disguise as a class skill to the following classes: Assassin, Bard, People's Champion, Rogue, Shadowdancer, Shifter.
-Updated the prerequisites for assassins to also need 4 Disguise as per PnP
Miscellaneous Changes:
-Changed whips and flintlocks so they can be dual-wielded.
-Changed muskets so they can no longer be dual-wielded (though a secondary item can still be equipped)
-Changed the damage types for Falchion, Maug Double Sword, Mercurial Longsword and Mercurial Greatsword from Piercing-Slashing to Slashing (was a bug).
-Added a new helm (194).
-Removed a buggy helmet appearance that caused crashes; the helm should now work properly (helm_028)
-Added new creature appearances, doors and placeables (egyptian content and skeletons)
-Added new religious themed placeables and items (shields 248, 249 and 250 and holdable amulets)