The new firmware drastically increases SD card transfer speeds.
The blue lights, pulsating on the front of Internet-connected Wiis worldwide, mimicking the call of the Japanese bush warbler, mean one thing: a new system update has arrived. Version 3.4 doesn't add any new features, but it makes a highly desired improvement as well as some smaller updates.
The enhancement that will affect users most, particularly those who download a lot of WiiWare and Virtual Console games, is the significant speedup of reading from and writing to SD cards. Wii owners have long griped over the inexorably long transfer times, particularly from Wii to SD. The update reduces copy times of larger files from minutes down to seconds.
The Wii's Parental Controls have also been enhanced. Furthermore, though it's not very text-centric, USB keyboard support has been added to the Mii Channel. Nintendo claims that the update also improves disc reading.
It appears Nintendo is now on the offensive against Wii hacking. Version 3.3 made an attempt to block the "Twilight Hack" method of homebrew loading, but a couple of bugs in their approach led to a second compromise days later. This update patches that exploit as well as the newer exploit, the PatchMii hack. Furthermore, Nintendo has changed their Terms of Service regarding Wii updates, allowing for future automatic updates of the console without notification:
We may without notifying you, download updates, patches, upgrades and similar software to your Wii Console and may disable unauthorized or illegal software placed on your Wii Console to ensure that your Wii Console is operating properly and efficiently, comply with applicable laws, assist law enforcement, protect us and our customers, or prevent the use and distribution of software obtained through improper channels.