Just tried:
cvs -d:pserver:mailto:anonymous@cvs.openacs.org:/cvsroot co -d xowiki openacs-4/packages/xowiki
Works for me ... you might want to add the "-d xowiki" switch after the co sub-command. this spares you to flatten the nested directory structure afterwards ...
There have been issue with the availability/reliability of the new hosting machines. I am not aware of recent ones ...
//stefan