I think statistics tell very little at this point, other than that Keen is a great player, witchdoctors are probably a little overpowered and barbs and wizards underpowered. I think it would be very interesting if the most active player of every class would write their own conclusions, not based on statistics but based on perceived balance.
As a monk, I think Keen is definitely beatable (i lost 1-5) but it will take amazing gear and play skill. My initial thought to balance this particular matchup a little is to ban shields on wd's, although I'm hoping of course Bliz will tune things a bit more so we won't need to ban anything ourselves.