There is a huge focus on PvP from the get-go. RvR scenarios will likely play a large role in the endgame. For those less PvP-inclined, it's unclear at the moment just how extensive the PvE endgame content will be. Public Quests are scattered throughout each zone and are largely part of the PvE content but can easily become PvP battlefields. PvP and RvR are better explained by this video podcast. And this one. Open RvR and Sieges are explained here.
The Tome of Knowledge is interesting. There is no way to finish it entirely but it should appeal to the "collector" in most of us; unlocking every entry, earning every achievement and title. There is a much better explanation of the Tome of Knowledge (and Public Quests) here.
Guilds are "alive". The more people who join your guild and the more tasks your guild's members complete, the more your guild is entitled to. This podcast explains it in full detail.
Crafting is sort of "more of the same", but also different. It's more involved like Everquest than it is a simple have the ingredients and click like WoW. Another video podcast gets into that, too.
More info will be updated to this post as it becomes available, and this post will likely be removed once the game is released.