the hex and octo core processors are meant to be on 2011, however, I wouldn't be surprised if at some point down the line they throw out a hex core socket 1155 CPU.
If you have the money for it and can wait (it will be pretty damn expensive), then it will, in theory, be worth the wait, but either way 1155 will put you over no problems for a good while, just make sure that you wait until late Feb/early march before building for when the "fixed" chipset motherboards are released