Warhammer Online's Game Update 1.3 (also known as the much anticipated Land of the Dead patch) has been locked in for release on the 16th of June, but if you plan on experiencing the new content the moment that it's available then you might want to consider pre-downloading the patch ahead of time. The pre-patcher file is 867MB's and is said to contain "the bulk of the update", meaning there will probably be a small amount leftover to download on the proper patch day. After opening the executable and installing, the game can be run as normal and the update will automatically activate itself when it's required.
The pre-patcher that we've been given so far will only work for North American and Oceanic game clients, but GOA will be bringing out their own version for European clients early next week. The NA and Oceanic file can be obtained directly from Mythic through this link.