EJB3 is in public review now and is expected to be final in september. (At least that was the word from Linda at JavaOne) I wouldn't expect much, if anything, to change between now and then.
I've said early that I think you would be safe with EJB3 for projects that have a 4-6 month dev window. For projects that will be done faster than that, I think you have some risk from changing specs and from implementation bugs. But, I am confident that after a few months everything will be stable and tested enough to deploy production EJB3 applications.
I've had an EJB3 app in production since the beginning of the month when we first released a non-beta EJB3 and haven't had any problems, but that's merely one data point.