I think he has the wrong mentality these days. I think after he won MLG he became kind of... content. Not really putting it all in anymore and just getting frustrated instead of motivated. Would love to see him getting out of that though!
Not sure what is going on in his mind, but his game is no longer the same when he was playing on par on the GSL. Maybe its a mental block of low confidence, but his slump has been going on for more than a year now with no signs of improvement.