I deleted a few system apps (all the social stuff, corp directory, email, etc). In a thread on DroidXForums (
this  one on the unrooting procedure) someone mentioned that they could not  get the .604 update without some of the bloatware. Of course, this  freaked me out a bit as I would certainly like to get Froyo when it  comes out. So, I went about trying to reinstall the stuff I'd  uninstalled. The system dump with all the default apps is 
here,  and below is the procedure to get what you're missing reinstalled and  visible as system apps. I used Root Manager but the same procedure  should work for Root Explorer. If you prefer ADB I'm sure one of the  more competent terminalists here can help you.
-Place the apk(s) of the apps on your sdcard.
-Use your chosen means to copy the apk(s) to /system/app (this will  require making /system/app writable. In Root Manager just press the R/W  key when you're exploring /system/app).
-You now need to change the app's permissions. In Root Manager, long  press on the app (in /system/app) and click on "permissions". Then make  sure that only the following boxes are clicked: User Read, User Write,  Group Read, Others Read.
-Make sure you make /system/app read only again by clicking that box in the top right while you're exploring the folder.
-Reboot phone.
Now the apps should be loaded and the system should recognize them as  system apps (you can verify by opening Titanium and noticing they're in  red). This should make you good to go for whatever OTA comes. If you're  unsure which apks in the system dump correspond to the apps you've  deleted, just explore your /system/app and compare it to the system dump  app list. Any apks in the dump but not in yours are what you're looking  for.