You can now have sex without paying for it by romancing party members (two romances finished so far). TONS of new party banter and side quests. Your party members won't just put out -- you gotta do some favors first.
https://www.youtube.com/watch?v=kHzbqdN2MdM
Also, you can now swim from Windside Beach to Berindal's Refuge if everyone in the party has the Swimming ability. Finally, added some new music and audio resources for later, thanks to Sonic Kitchen.
Complete list of changes:
-You can now have sex without paying for it!
-Finished party banter/romance in Chapter 3.
-New tracks from Sonic Kitchen: highway, dungeon2.
-New sounds from Sonic Kitchen for future music minigame.
-New sprites for ancient lab, workbench, forge, and table.
-Added transition between Berindal and Windside Beaches in Ch.3 if entire party has Swimming ability.
-Removed a couple waypoints and mobiles from market maps in Ch.2 to increase performance.