OpenSolaris have 2 print systems, the default print system to date including 2009.06 release is LP. From the Live CD, the LP print system is installed. You may want to have CUPS because of better application integration or other reasons. You need to install additional packages from the repositories, such as http://pkg.opensolaris.org/dev.
To avail of the CUPS print system, one needs to do the following steps:
$ pfexec pkg install SUNWcups SUNWcups-libs SUNWcups-manager SUNWpycups SUNWhal-cups-utils
$ pfexec pkg install SUNWhal-cups-utils
(All the relevant pkgs will be installed based on dependencies)
NOTE: SUNWhal-cups-utils was integrated into build 114, so you need to have that version or later).
Once these packages are installed, do
$ pfexec /usr/sbin/print-service -s cups
(The print system is then switch over to CUPS)
To revert back to LP, simply do
$ pfexec /usr/sbin/print-service -s lp