When Sun started the process of open sourcing Solaris 10 about three years ago, it sufficed to have a website dedicated to programmers. OpenSolaris.org was the place where OpenSolaris was being built, and for a while, according to Dan Roberts, director of product management for Solaris and OpenSolaris at Sun, this worked out just fine. However, later on, people expected something else on OpenSolaris.org: a distribution. "They were looking for something that they could understand, that they could deploy, that they could use."
He continues to explain that Solaris 10 was mostly a monolithic package, a very complete operating system filled with stuff that a lot of people simply don't need. More or less he said that Solaris 10 was a bit overkill if you just wanted to deploy a php application on Apache. The new package manager is part of trying to solve this problem, to make Solaris 10 less monolithic. The IPS system also uses ZFS; if your package upgrade goes tits up, you will be able to roll back to a stable system using ZFS snapshots - you can make a ZFS snapshot right before you start the update process.
Jim McHugh, vice president of Solaris marketing at Sun, explains a little further:
And they're going to update the default shell to understand the backspace key. Just so you know.
You can download the new release from the OpenSolaris.com website.