"Do Not Delete" the distmdl files !
Several months ago, I took the advise of someones post and deleted these "for replication only" files. However, the lastest MS hotfix fails because it can not find these files.
If you look at the resulting log files in "C:\Program Files\Microsoft SQL Server\90\Setup Bootstrap\LOG\Hotfix" folder you see the following messages:
1. "SQL Server Setup did not have the administrator permissions required to rename a file: d:\MSSQL.1\DATA\distmdl1.ldf. To continue, verify that the file exists, and either grant administrator permissions to the account currently running Setup or log in with an administrator account".
2. "Unable to get component path for component distmdl.3D37F4F2_DA2F_4972_97D0_34767EB5DA29 distmdl1.ldf"
Bottom line is that the distmdl files need to exist for updates/hotfixes even if you do not implement replication.