I don't mind knowing the Pokemon beforehand. I always know every Pokemon before release since they always leak anyways. The fun part will be playing the game and actually making teams with these new Pokemon. If I really wanted to be surprised by the Pokemon themselves, I wouldn't be clicking on these threads.
Admittedly it's not a huge problem for me, but I've seen enough people including friends who are bummed about it where I wish they'd ease it up a bit.
I'm just salty that we're finally getting worldwide releases, which means for the first time ever there actually is decent potential for a surprise while playing the games in the west, but now they've decided to reveal all the cards before they launch.