Play WiiWare from USB Loader
UPDATE June 13, 2010
emuhack has posted a guide on how to run WiiWare/VC from a USB Loader - LOOK HERE
Kallstar, at GBAtemp, has developed a way to load WiiWare games from a USB Loader. The way he achieved this is by creating ISO forwarders. As far as I know, you will need to install TriiFroce_mrc to get the IOS forwarders to work. Visit the tutorial by Sinyk to install TriiForce_mrc - LOOK HERE.
The ISO forwarders are nothing more that forwarders in an ISO format, that will boot the WiiWare you have installed with TriiForce_mrc. The ISO forwarder gets installed to the USB loader just like the way you would install a game ISO, using WBFS manager or a similar WBFS tool. The size of the ISO forwarder is 1.76MB.
After installing the ISO forwarders for the Wiiware you have installed with TriiForce_mrc, you will probably want to install some cover art to look at in the USB Loader menu. Kallstar as also created a cover art package. The cover art gets installed to the same folder where your Wii games covers are located. You will also need to edit your Titles text document, for your usb loader, so the text of the game description will appear when in a cover flow type of usb loader menu.
To download the ISO forwarders, covers art, and codes for Titles text you will need to visit Kallstar's post.
Source - kallstar - triiforce mrc - GBAtemp.net