According to the web site, availability in the United States is from NewEgg and TigerDirect. However, I don't see either of those carrying this card yet, so I'm not sure when the card will be available to buy.
Also, does anyone know what kind of reputation the GeCube vide cards have?
It's not just a standard XT either. From the press release:
It uses an ATI RADEON R580+ GPU with GDDR3 256MB and comes with GECUBE’s exclusive X-Turbo fan, built-in Thermo Electric Chip (TEC), and temperature-controlled devices. The core clock speed not only directly challenges that of the X1950XTX level (648MHz), its overclocking speed can also reach at least 675 MHz or even higher.