when can we download it ? 
In July, Pixologic will unveil ZBrush v1.5 at Macworld Expo in New York, and Siggraph in San Antonio, Texas…
probley towards the end of the month you can download it…
Thanks, EZ.
Shortly after those two conventions (Siggraph ends on the 25th, if I remember right) we will be contacting all existing users with information on how to receive the free upgrade. And, of course, it will be announced here that it is available!
ZBC will continue to show occasional sneak previews of what is in store with the new version, as well.