Hmm its speculation but maybe with voltage unlock the card passes 300w ? It clocks like mad at those volts but AMD couldnt release it like that so they give the option to keep TDP under 300w ?

Cant wait seems it wont go faster than 580 ..... also maybe delay was to finalise clocks from 800-880mhz ? maybe at 800 it would have been too close to 570 even and AMD adjusted for that. 570 and 580 are pretty close anyways if this is going to be inbetween them its probably gonna cost ~420$ ?