If you use the daohub.org to create DAO via Eth, they want you to send ETH to some addy, 0x123.....
So who owns the private key for the newly created DAO and how do you access them? I feel like ETH just sent off into the ether ... I'm still a little confused.
Don't worry. As long as you use the right kind of wallet (i.e. myetherwallet or MIST) then the DAO becomes automatically associated with your sending address and is associated with the private key of your send address. Only you should have control of that private key. The whole process is automated. When you are using an exchange like Bittrex then obviously they are in charge of the private key so you have to trust them.