Well, the patch looks okay, but a couple of comments:
1) When adding new built-in deeds, I have put in framework for incrementing the "version" of daily deeds and thereby automatically adding the deed to people who upgrade from an older version (currently version 0). Look for the code up top that checks dailyDeedsVersion, and my comments in there.
2) I don't think this needs a new built-in deed. Simple deeds that just track a preference can be implemented by the user with custom deeds.
2.5) If you were implementing this as a built-in, you would want to add an item listener and setVisible( false ) if the user does not have the item. Similarly, a custom item deed is capable of doing this.
3) What you might want to do instead of making it be its own deed: consider adding it to the already-existing DropsDaily deed. Use the above advice to set the visibility if the user has the item.