Official quote from Anet…
Advance notification of new builds
In order to allow WvW players to make good decions about siege placement, assault timing, etc. we’re adding a new build pre-announcement. This will be in the form of a message broadcast to all players some time before the current build expires. Because this notification is tied to one of the final steps in our build process, and those final steps take a variable amount of time, we won’t be able to say exactly when the current build will expire. Instead, the message will provide a window of time in which the new build will become available.
Please pull it together Anet. This is what will in the end cause you to hemorrhage customers until the game we love is just a shell. A 935kb DL? This can’t be serious.