What about exchanges? Can I just leave on balance and It will be OK?
Depends on how competent are the guys behind the exchange.
I would not trust them my coins until they migrate to the new wallets.
But that is way I'm...
Migrating your coins to a local wallet (running on your computer) makes much more sense to me.
Just make sure you are running the new wallet (0.8.6.5).
mintpal and cryptsy have confirmed that they are aware of us forking and will be prepared.
to be %100 safe you should always be in control of your own coins.
not to spread fear, if you have no other options but leave your coin in the exchange then you should be okay too.
if you have no means to sell/trade your coins anytime soon my personal advice would be to move your coins in your wallet anytime a hard fork is being executed
cheers
-Who
Cons-e also confirmed they will be ready. I recommend to not keep coins at Comkort and Bleutrade, until they also confirm the transition. Only xhash.net confirmed they will be ready for this transition. I recommend only them and other p2p pools to be written on OP. All other exchanges and pools should be removed from OP. Seems they are not interested and are managed by amateurs.