*shrug*
I'd love to see one in play, and the class has finally caught my attention, but I have to agree there's something wacky in the way it works. The two biggest flaws are...
(1) Blurred Step is an Opportunity Action. Unless you buff it with certain feats or magic items, this doesn't help all too much; ideally it should enable OA's, not replace them. Also, the fact that it's an interrupt instead of a reaction makes it insane. Changing it to a triggered free action would, IMO, make it an awesome and useful class feature and would make them suitably sticky.
(2) They have no way of making capable Basic Attacks, unless they take Melee Training. This was pretty okay for a Swordmage, since there was a Strength build which relied on Basic Attacks. For a Battlemind, whose powers are geared towards OA's, it's a feat tax. Not a huge deal, but there you have it.
Otherwise, I largely disagree with the CharOp folks. I think their marking mechanics, Mind Spike, etc. are fine.
-O