Looks like a dutch webshop is already selling the i5-3570K cpu. It is not a pre-order and they have them on stock (if I can believe their website ).
It is only for sale in combination with a motherboard and mem kit, but the fact that they sell it..
Link: https://www.cdromland.nl/productinfo/270125/Intel/Processor_Intel_Core_i5_3570K
I bought one, and already received E-mail that it is on its way to me, so I can expect the cpu tomorrow ! Gene Z77 is already waiting!