Fudzilla credits an Australian reader who "stumbled upon Gigabyte's HD 5770 is listed [sic] in an Aussie shop." It's not clear whether the photo was taken in an actual store, after an early sale, or otherwise, but in any case, the card looks almost conspicuously similar to Gigabyte's existing Radeon HD 5850.
Both cards have similar dual-slot coolers and the exact same port array: two DVI stacked on top of each other, with DisplayPort and HDMI outputs sitting below the fan exhaust vent. Only the stickers on the cooler and above the PCI Express x16 connector identify this card as a Radeon HD 5770. The circuit board looks a tad shorter than the 5850's, too, but the perspective makes it hard to tell for sure.
According to Fudzilla, this purported Radeon HD 5770 was selling for $262.90 AUD, or around $234. Like in Europe, however, Australian prices seem to be a bit higher than in North America. The European listings we came across yesterday suggest that the 5770 will cost less than $200 in the States.