From Camel, The Main Developer of DroidMod, on his website yesterday, forum.droidmod.org. The bottom line is, if you have rooted with DroidMOd, don't worry about the 2.1 update appearing, you can click download if you want, but it will not install, and you can wait until DroidMod has a new update, nothing to worry about: He states:
"DroidMod does not block the download of the update.zip because renaming otacerts.zip causes the phone to constantly re-download the file. The update is blocked by sprecovery - but, actually, even if it were not blocked, the update wouldn't install anyways be cause the pre-install checks internal to the update would all fail.
So don't worry about the update; eventually it will force you to attempt the install anyways, which will be blocked, and you'll still have DM 1.0."