yes, it is possible, but it would mean that the usb ports on the wii be unlocked to full speed (USB 2.0), and a suitable loader, its only a metter of time beofr one is developed, but until then, we should stop asking.
its like the psp's homebrew scene, it wasnt long before we got a iso loader on that, so its only a matter time before one appears for the wii, then the real piracy scene begins and nintendo will stop all our fun for good
as for a GC freeloader, its an awesome idea, but i wouldnt know if it is even possible, i have a few NTSC and JAP gc games i would love to p;ay again without a freeloader, but if it is possible, its until someone takes on the task of coding the program