I am quoting this mail almost in full because it is so typical: "CVS sucks! Let's switch!" This is so irrevelant -- everyone on this list is aware of the shortcomings of CVS without taking Drupal in regard -- most troublesome is the lack of version controlled directories and renames. But the problem is that we NEED to take Drupal in regard. And then the questions to answer are: Why do we want to switch? To answer that, list the current problems of our contrib authors. Go out and do the research, ask them. How will git or Mercurial help solving those? E.g. people who do not get at all what a branch a tag will have less problem with this when facing all the possibilites, say, git offer? Think of human issues here. Think someone who needs all her wits to put together a module or the template.php of a theme and then needs to fight the monster an RCS is. Can you explain the multiple heads in Mercurial to her in a very simple way? Let me doubt.
I agree with Karoly that Git (or bzr or Mercurial or...) is not the answer to all our problems. Especially the lack of good, stable Windows/Mac GUI clients for all the aforementioned systems is a big showstopper. TortoiseHg is out, but still very much beta.
I think the keyword here is _eventually_. I hope that we can all agree that CVS is past its prime. Its many predecessors hold many advantages over it. Many new features that CVS will probably never get. So while we're not in a position to switch to something else right now or this year, it would still be wise to consider the future.
I could rant endlessly about why distributed SCM is great and boosts productivity, makes it easier to try out crazy ideas. Makes branching and merging easier and so on, but I suppose you all know this.
So all I'm saying is that we ought to consider switching to something else at some point in the future, because CVS isn't that great now and is not likely to get better.