I tried the same command and all the packages refused to be downloaded. Ug. It appears that there is a bug in cvs when (somtimes?) using the "-d" command with "checkout".
The development tree is actually not a branch, but simply the most current version of the trunk (aka HEAD in cvs-speak). cd to a temp directory and issue:
1. "cvs -d :pserver:firstname.lastname@example.org:/cvsroot login"
2. hit return for the password
3. "cvs -z3 -d :pserver:email@example.com:/cvsroot checkout openacs-4"
And you will get the HEAD version. Then move/rename the "openacs-4" directory.