Actually telling it to download and install later has an additional flaw.... you can only download it for the OS your currently using.
Most of us will have a desktop with say WINXP and we are wanting to download this to install on a win2k server without tying the server up. We then burn it to CD and carry it to the server after 5pm when the users will not lynch us for rebooting the server. This allows us to complete the install in just a couple mins instead of the normal time consuming download/install that microsoft wishes us to use. Since this is of course all happening after hours (5pm) and forcing the techs to work overtime the really want it over with ASAP ;-)
The command line trigger is the best way I have found... but every time I go looking for the command line switches I find it in a different spot on the web ;-)
Thanks for posting this here,
Chris