VC's will never take up a 20gig hd. Are you insane? Even N64 games arent even 100 megs. You would be able to fit hundreds if not thousands. Even on my xbox 20 gigs is more than enough and they have alot of downloadable content and expansions that take up a whole gig. VC/Arcade games are very small. Most if not all are less than 50 mb.
Wii needs to improve online and 3rd party. THEN work on a external HD.