This morning I checked my Wii because the blue light was on, and lo and behold there's a system update!
This time around Nintendo's getting brutal. This update deletes ALL homebrew, the Homebrew Channel, the preloader, bootmii, and blocks any homebrew from being reinstalled. Additionally, there are performance tweaks and an update to the Wii Shop Channel.
Source 1: My WiiSource 2
Note: Hear Mii does not condone hacking or piracy, but we understand that there are legitimate uses for the Homebrew Channel (i.e. the camera hack for Super Smash Bros. Brawl).