You have a link to the system dump? Ive looke every where for that stupid blockbuster.apk. the one i found was for 2.1 i belive and wouldnt install
The market version won't help you get the OTA update, it needs to be the one it came with because it's installed as a system app.
Don't worry though, just download a X2 system dump, (there are several people who've uploaded it) find the file in system/app and copy it over to your phone with root explorer, set the permissions and reboot.
Sent from my DROID X2