Neal Gafter: "Sun has a mechanism in place now to get you an alpha of the entire J2SE 1.5 platform every two weeks (linux, solaris, and windows). This will give you a chance to try out the new language features and APIs.
To sign up, send e-mail to Ingrid.Yao@sun.com, asking to be added to the CAP program. Tell her Neal Gafter sent you to sign up. She will send you a nondisclosure form to sign and FAX back. Once she gets it back from you you'll get access to a web site that has a new alpha of the entire J2SE platform (solaris, linux, and windows) every two weeks."
I sent my mail :)