Anet is not making any card game (except for what Jeff Strain said long ago in an interview "we have something in the works but i'll not announce anything yet") but they are just representing skills with cards for players at the event to use to make their builds.
I'm a great fan of sealed deck in mtg and i'd really love to see this type of pvp implemented into the very game, without the need to use any cards, and for everyone have a chance to play it. This would be such a skill intensive format, with a little luck factor involved aswell.
And how about making the first preview event for GW:Nightfalls a weekend of mini sealed tournaments? That would be awesome! A great way to have a glimpse at new skills and a chance to play them without the need of unlocking them yet. It would be sooo much better than the first PvP for everyone GW:Factions Preview Event. (the sealed-play would be an additional feature for a pvp preview event, with the ability to unlock new skills for gained faction; and after that a big pve+pvp Nightfalls event would follow for sure)
... i like dreaming
