The Wad Manager is run BY the Twilight Hack.
The WAD Manager can be run by:
The Twilight Hack
The Homebrew Channel
The WAD Manager Channel (installed as a WAD with one of the two methods above)
The Twilight Hack isn't really a necesity here, which is what mousan is asking. However, there is no reason not to use the Twilight Hack to install the Homebrew Channel because they both end up being channels on the Wii Menu, and one might have trouble auto-updating if it is installed as a WAD.
QUOTE(Arm the Homeless @ Jun 22 2008, 07:59 PM) And installing via Wad Manager might brick your Wii.