My ONLY question about Wii 4.0 update.

Do installed WADs still work?

If anyone has actually been tempted to update and try out their wads... that's all I'd like to know.

yes they do, i would advise that you update with waninkoko's "Firmware Updater 4.0" though because then you can patch IOS60 to enable your wii to play "unofficial" wads from the SD card menu.