I tried searching but cannot find an expected date of Zend Framework 2 official release.
Is it safe to use it for a project which will go live in August?
As said above, it depends on how you define "safe", and your kind of project.
If your project is going to be deployed into production, however, it doesn't look too safe to me. According to last beta release note:
The beta release cycle is following the "gmail" style of betas, whereby new features will be added in each new release, and BC (backward compatibility) will not be guaranteed
So, if you still want to have a try, you have at least some options:
Hope that helps,
ZF 2.0 is a very good tool but how do you define safe? ZF2 is not well documented and it's not official released which means you will not have the support you'd have if you were using ZF1.11.11 or Symphony2
Is there a specific reason you want to use ZF2?
Zend Framework 2 is still in development/beta stage. what it means is they are still adding/changing the API. i personally would never go for beta versions for development purpose. but i would rather say it would be good to explore the features/updates just to understand what might be in the box for me in the future when it will be ready for development purpose.