phantastic91 said:
http://gonintendo.com/?p=46446#comments
these people in the comments said that it affects homebrew =/
Um nothing is confirmed there, someone just posted that you could delete the news/weather/photo channel and save 53 blocks, and "It’s something about Miis, plazas and parades, and unauthorized save data management."
And then someone speculates that you can't use homebrew. I'm guessing if the saves aren't signed then it won't work right. So VC/WiiWare should be fine, just the Twilight Hack is probably fixed. Though I'm sure it's not fixed good, I have a feeling it just checks like an MD5 or something on the known saves, an update could easily be made.
Until something is 100% confirmed file this under Speculation/Rumor.