The first trailer is an orchestral mash-up of new locations, combat, and creatures, whereas the second trailer has members of the development team explaining the contents of the expansion in more detail.
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You can grab the patch from FileShack, and peruse the fifty pages of patch notes detailing the new features and enhancements. Some of the most notable changes include an increase in the player level-cap from 50 to 55, three new zones for both PvP and PvE gameplay, and a beefed-up experience system that makes it easier for players to level-up. A new "windstream" system has also been added, acting as a sort of expressway that makes flying from place to place less of an ordeal.
A new "Pet System" has also been added to the mix. Some pets craft items, and some provide an extra inventory slot or warn the player of nearby danger. Purebred pets can do a combination of those things.
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