The big failing of DVCSen is that you lose the ability to do fine-grained ACLs on code. For example, if a company wants to restrict access to certain parts of their codebase (eg, megacorp brings in contractors, they should see only the one tiny part of the code they work on), you can do that in svn, whereas with git you can't give them access to part of a repository. Heck, you can even integrate your ACLs with Active Directory if you have enough LDAP/Apache config fu.

Also, it makes pointy-hair types more comfortable to have a central server where everything is obviously canonical.

I don't think DVCS will ever fully supplant centralized systems (including Subversion, Perforce, and whatever else people use these days) in the corporate world.