I like new stuff and
Heroes Hold will replace Grave Yard. The transition quest is a server-wide quest in the making to bring in HH. Instead of just dropping HH in all of a sudden, the quest have the players involved in the change-over, which will take some in-game time. Hopefully the quest itself will be fun for the players as well.
One dragon is for a specific quest, which will bring in 3 new maps, connect Somber Cave to Hurnscald, and give the players a new pet. The other dragon is because you can never have too many dragons, and the two act entirely different.
The current GY quests will have replacements, although it is still up in the air as to whether or not all of the unique rewards will be available from HH or in other ways.
No items will be removed through this transition.
The Idle Zone is where everyone likes to hang out. On TMW that has become the Hurnscald town square because it's bigger and generally better for idling; in LOF it's just south of Tulimshar because that's where the portals are. However, the space, while we did add some benches, could be better. We'd like to revamp that map and also improve the portals.
The trade routes will essentially be land bridge v2. George speaks of the ferry system allowing merchants to avoid being eaten by Wolvern, which indicates that there is/was a trade route between Hurns, Tulim, and Nivalis. It'll give the world some more depth and give us maps to place some quests and monsters we'd like to deploy.
Hope that answers your questions!