On September 1st, Koei Tecmo will release the update for Hyrule Warriors that they recently mentioned over Twitter. This update will fix a variety of bugs in the game, and will add a Challenge Mode to the game. It also gives Link a new 8-bit-style sword, whcih you can see in the screenshots of the update below.
The patch will update Hyrule Warriors to version 1.2.0. Note that this is primarily an update for bug fixes, and that some sort of larger update with more content for the game is in development, too. That will be released at a later point in time.
A new Sword weapon for Link:
BGM Setting feature:
This feature allows you to change what music plays during a particular mission.
Whether or not this update will be included in the base game when Hyrule Warriors releases in the West hasn’t been announced yet. The game will be available in North America on September 26th and in Europe on September 19th.