Wouldn't it be better if the System-Config-Printer-Applet would do this? I heard that this applet will be able to download drivers so it doesn't seem to be a problem to let the applet install some packages.
The problem with Jockey is that it is AFAIK only started on startup and doesn't react on hotplugging.
An alternative could be that the printer applet calls Jockey to install this packages. This probably will even be the best solution.