@It seems tough to get too excited about a package manager,
No, it does not.
Packaging is Sun's biggest weakness and one of the main reasons why Linux is beating it.
It does not matter how great the internals of an OS are and how many cool features does it have. It will not penetrate beyond the organisations which can afford 50K+ sysadmin packages if its packaging sucks so bad that people are willing to port other OS package managers to deal with its failings (people used to port debian package manager to do manage solaris in the past).