In a DVCS, each developer has an entire repository on their workstation, to which they can commit all their changes. Then they can merge their repo with someone else's, or clone it, or whatever (as I understand it, I'm not a DVCS user).
To me that flags a side-effect, of being more vulnerable to forgetting to backup. In a traditional centralised system, both you as a developer and the people in charge know that if you commit something, it's held on a central server which can have decent backup solutions in place.
But using a DVCS, it seems you only have to push your work to a server when you feel like sharing it. It's all very well you have the repo locally so you can work on your feature branch for a month without bothering anyone, but it means (I think) that checking in your code to the repo is not enough, you have to remember to do regular pushes to a backed-up server.
It also means, doesn't it, that a team lead can't see all those nice SVN commit emails to keep a rough idea what's going on in the code-base?
Is any of this a real issue?
