True enough, but for work within your company these conditions are likely already met. And while your company could easily have an internal central repository server (we use RhodeCode in our lab), not everyone might want to (or have permission to) push into the central repo.

I know a company that essentially only commits changes to their subversion server once they're ready to be shipped to the client. Their developers just work on (unrevisioned) private copies and distribute changes to one another manually. Makes me cringe. I've been introducing some of them to DVCS as I interact with them (they send me a zip file full of code to look at, I send them back a link to a repo containing their zip file contents and my patches), but I don't think they're quite getting it yet.

LDAP/kerberos (or similar centralized account system) or "anonymous" account (no password) alleviates auth problems. Routing traffic to the machines is as problematic with HTTPS as it is with SSH. SSH tunnels can be used instead of pagekite.