Yeah, that part of card games is tricky. Magic the Gathering got it working, but honestly I think that was more a right place at the right time thing. They were the first to get big, and so they can stay big.
Not taking away from the designers but I think they once had a quote from a designer who wasn't thinking who said something like "50% of the set are throw aways, 30% are reworked versions of similar cards and 20% are playable."
Heh and those 20% are almost always the Super Rares. The way they have it set up prevents "Power Inflation" which is a better option since then atleast your old cards can be used in casual games, but I don't think you can get people in on that ina new game. It'd be like the whole Starwars Galaxies thing all over agian now a days.
