After adding OpenIndiana b148 as a new boot environment, I have found that my system is experiencing unexpected freezing.
There does not appear to be a pattern that I can discern or a common triggering action, in most cases if I wait the system will recover.
Yesterday, I was trying to change the settings for the Screensaver adjusting the time before the screen would lock. I could press the button to change the time (nothing appeared to happen) then about 1 minute later the screen updated.
If I switch back to OI_147 I do not have this problem. I am using the save Nvidia driver release in both boot environments.