To test OpenACS 5.2 you'll need to check out from CVS HEAD until we branch.
If you have a cvs account
cvs -d:ext:mailto:username@cvs.openacs.org/cvsroot co openacs-4
or anonymously
cvs -d:pserver:mailto:anonymous@cvs.openacs.org/cvsroot co openacs-4
will check out every package on HEAD.
To just get OpenACS core packages
If you have a cvs account
cvs -d:ext:mailto:username@cvs.openacs.org/cvsroot co -r HEAD acs-core
or anonymously
cvs -d:pserver:mailto:anonymous@cvs.openacs.org/cvsroot co -r HEAD acs-core
or