I moved my bitcoin from kraken to bittrex about two hours before this was announced. I just got the email from kraken that they'll support the fork.

It sounds like each exchange will handle it a little differently especially regarding short positions and margin traders. I think I read somewhere that bittrex won't automatically assign short positions in the new bitcoin cash to people who are short bitcoin going into the fork while kraken will. I just have a small long position (no Margin for me ) so I'll just take what I'm given and be happy with it.