FWIW, my personal opinion is that nothing should be committed to CVS unless it works. That doesn't mean it has to be fully tested and ready for release, but I don't think the publicly accessible CVS repository should be used for incremental commits while a package is under development. That's what local CVS repositories are for.
I think that anything that's in the public CVS should install and drop cleanly, and should be in a state where there is a *reason* to make it publicly accessible. Usually that would be to ask others for their opinions on how it is shaping up so far, or to ask for suggestions on how to implement something, or maybe to ask for help with testing.
I just don't see how it benefits the project to have a package under active development, which really isn't useful to anyone, made publicly accessible. Especially since one of the first mistakes all newbies make when they try to check something out of CVS is to forget the branch tag. A newbie who checked out HEAD today would be in for quite a shock!
Just my $0.02...