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I was at PAX East and had the pleasure of playing it. We went to the big announcement and you could have heard a pin drop in the theater when they revealed it was a TCG. Then they began to show use more about it and told us it was playable on the floor. My friends and I went to the booth, played it and absolutely fell in love. I don't play TCGs, and some of them don't play any MMO's. We literally used the booth like an amusment park ride, any time we walked by and the line was reasonable we got on and played. I probably played over 15 games in three days of PAX. It's an absolute winner.
Also, one of the guys who works on balance was there - mad cool Asian guy (forgive me for not knowing what specific background). If you were losing hard to the guy playing you on the other side of the wall, I called the balance dude over and he showed me what the best moves were to turn any game around. The game has ridiculously indepth. And that team is crazy passionate about the game.