The Fostex TH600 is good news. I know more than a few people who have been wanting to get the TH900 but didn't want to pay the premium for the lacquer cups. This seems to be the answer for those people, assuming Fostex doesn't do something stupid and tune them to be way more colored than the TH900. If they retain the sound of the TH900 but end up costing half as much, I think they'd be a pretty good buy.
Given the loss of the Denon AH-D5000 / D7000 and their downright awful (IMHO) successor, the D7100, it's nice to see the TH600 potentially filling that void. Basically what the D7100 should have been with its claims of "flat tuning!"
That being said, I think the TH600 will have some competition:
....from the upcoming closed-back Audez'e headphones, assuming they're both priced around the $1k region.