Not overly enthousiastic overhere looking at those new SONY flagship headphones... They look a lot like my CD900ST. Very very similar cup size and design, closed back, studio oriented. Yes, overall built quality looks a lot better, but to be honnest, the CD900ST feels like a chinese toy in your hands; all plastic and lightweight. As Leepeery stated, the CD900ST earpads are fragile, and those earpads seem strangely alike.
However, mainstream SONY products usually offer excellent quality/performance ratio, so we indeed can expect some good sounding headphones at the very least. I for sure love the sound of my CD900ST. And I also agree that it is positionned at a very interesting pricetag. Beeing 3 times the price of the CD900ST, and considering how good the CD900ST already sounds to me, these could be a killer.