In addition to a new launcher, new Wildermore region, continuation of the epic storyline with Volume III: Book 10, and an improvement to mounted combat, the most important thing to come to any LotRO patch since launch is the removal of Lalia from the cursed Barrow-downs. Seriously. Bob's aggro-magnet daughter and her cloak have retired from frustrating players and she now owns her own shop in Bree. Where she sells MISERY. Just kidding. I think she sells Beanie Babies or something.
Be sure to check out the entire patch notes in the official forums.