You can dry-test without a printer (or you can test also with non-HP PCL lasers):
Do simply:
sudo dpkg -r hplip
With the HPLIP packages from gutsy-proposed this should give you an error sue to hpijs needing hplip.
So with hplip staying installed
ldd /usr/bin/hpijs | grep libhp
should not show any problem any more.
You can dry-test without a printer (or you can test also with non-HP PCL lasers):
Do simply:
sudo dpkg -r hplip
With the HPLIP packages from gutsy-proposed this should give you an error sue to hpijs needing hplip.
So with hplip staying installed
ldd /usr/bin/hpijs | grep libhp
should not show any problem any more.