It looks like you're new here. If you want to get involved, click one of these buttons!
Details are here:
Baltic Sea and Gold Coast are part of Vinland, which they said they added in March. They only added part of Vinland in march, and now they're adding the rest of it.
The Baltic Sea patch is basically the end of the Vinland quest line. The four items that they show discovery cards for are seriously high end gear. You can't even pull the quests until you've done a bunch of prerequisites, most notably a rank 14 geography quest. Mjolnir itself comes from a rank 15 archaeology/unlock quest.
The Gold Coast patch is a bunch of other scattered adventuring quests. Those are lower level, and none of them are above rank 10.
The new +4 furniture requires some item that may or may not be in the game in order to construct it. I somewhat expect the item in question to appear in the item mall shortly. But it wouldn't surprise me if the furniture is simply impossible to make, even though it's nominally in the game. There are already other items like that, as a result of releasing expansions out of order.
There are some new item mall ships, most notably including the "festive" Ironsides that you knew was coming. You can build a normal Ironsides, but you can't use it yet, as it has level requirements of 69/65/70, as compared to a current level cap of 65/65/65. No, really. I'm not making that up.
Treasure box is item mall stuff. Netmarble wants to make it so that nearly all real players can buy stuff from it, but gold sellers can't buy stuff from it with stolen credit cards that will charge back any purchases that are made. They initially had a total level requirement of 50. They reduced that to 35 for a while, then increased it back to 50, presumably due to abuse from gold sellers. Now, they're changing the requirement to 10/10/10, since real players usually get there pretty fast, but gold sellers tend not to level adventuring very much and not to level battle at all. They naturally level trade a lot in the process of farming their gold. This is an anti-gold seller measure, and not something that will directly affect most players.
Schools have been changed to be somewhat gentler. Some things were made easier and less repetitive. Most notably, the game's only "kill ten rats" quest has been changed from 20 battle galleys to 10.
World chat is now free to everyone, rather than being an NC item as before. Because having chat be an NC item means that even people who pay for it won't have many people there to chat with.
Job quests are now supposedly easier to pull. I've probably had about 30 or 40 pulls in which I could theoretically have gotten the cartographer job quest, but the game has never given it to me. On the other hand, I get offered the thief job about every third pull or so in London, which is too much, really, as I want to see other quests.
There's also an important undocumented change: they fixed the font. The row of garbage pixels that was under a lot of characters has been removed.