Expreview managed to score some pictures of the upcoming Zotac GTX 580 Extreme Edition card featuring a non-reference PCB design, 16-phase VRM, high-grade chokes, capacitors, POSCAPs and prodalizers, but unfortunately, we were informed that this one is only for Asian market, at least for now.
Nevertheless, the card features a large aluminum heatsink covering PCB components like MOSFETs and memory chips. The entire card is cooled by a rather large cooler with two 12cm fans. To accommodate the 16-phase VRM, the card has a different PCB which is a bit taller than the reference one, but still needs 6- and 8-pin power connectors.
As noted, this card is for Asian market and it won't show up in Europe or the USA, at least not yet.
You can find more pictures here.