I just got back from overseas, I got to hear the MA900. I wouldn't place it on par with or above the HD650, but its certainly a step below. This is an excellent set of headphones and Sony just replied to me and said they will be shipping my set out for review tomorrow. Look out for my review, I'll post a link to it here when I am finished. I really liked these headphones, my predictions weeks ago about them were spot on.
Glad that Sony will send you one for review too. Can't wait to hear your thoughts.