Vista - Print Processor Configuration , 32-bit VISTA

In Windows XP, SP2, a print processor is an attribute of a printer instance
and not of the driver .The registry entries for the driver do not have the
name of the print processor. However, the associated printer instance has a
print processor entry. This means that multiple printer instances that target
the same printer driver can be attached to different print processors.

In VISTA, we can see a new “Print Processor� attribute in the registry
associated with the driver and also associated with the printer instance. Is
association with the printer instance for backward compatibility?

If the print processor is also associated with the driver, does it mean that
in the long run, the print processor would become a driver attribute (like
the language monitor)?

Why we have the new print processor entry for the driver? Also, the
AddPrintProcessor API does not change the value of the print processor
registry entry that is associated with the driver; the change is only made to
the printer instance. Is "AddPrintProcessor" the right API to work with on
VISTA?