I just tried the newest version of Del Repository Manager for clients and it's awesome! I'm using it with DCSU but not the graphical interface, only the command-line interface for SCCM.
So I created a new rep and downloaded needed updates. Saved the catalog.xml in it.

then on a client, installed Dell client system update 1.2 (12/27) with /s /v/qn. That installed, I tried the command-line: "dcsu-cli.exe /silent /log c:\windows\temp"

I'm getting:
Status: Failed
Error: Error occurred while copying file.

So it sees the drivers and updates it must install on the network repository but it cannot copy them on the client. (In my settings.xml the files must be copied to c:\windows\temp).

EDIT: This is the output from the command-prompt:

C:\Program Files\Dell\ClientSystemUpdate>dcsu-cli.exe
Check for updates started...
Checking for application component updates...
No application component updates found.
Scanning system devices...
Determining available updates...
4 update(s) were found.
Downloading update (1 of 4)...
Downloading update (2 of 4)...
Downloading update (2 of 4)...
Downloading update (4 of 4)...
Downloading update (4 of 4)...
Downloading update (4 of 4)...
Downloading update (4 of 4)...
Download Failed: R267389 (Driver)
Download Failed: R254689 (Driver)
Download Failed: R278544 (Driver)
Download Failed: R272000 (Driver)
Error: Check for updates ended. (Downloading updates failed)