Indeed... Cryptsy did recently stake a bunch of blocks so hopefully they at least will be coming back online soon, bittrex is waiting for the error to go away which should as soon there are enough upgraded wallets/nodes online to outweigh the old ones. I have no idea whats up with polo.
Polo is back online now.
Polo is back online but bittrex and cryptsy remain disabled?
We know that bittrex won't come back for awhile, not until the old nodes/wallet error goes away. Cryptsy likely just taking their sweet time, we know they have the upgrade wallet up and running because I watched them stake a TON of coins not long ago.