I was asked by Beranger in a comment to the last post if OpenSolaris 2009.06 would detect and automount USB drives. Yes, it will. See the screenshot to the right.
This test was conducted using the LiveCD only. The USB thumb drive I tested this with was an older SanDisk cruzer micro 1GB. It was formated as FAT 32. When plugged in the desktop mounted the thumb drive fairly quickly, then popped up two dialogs; one informing me I had installed an Audio CD and asking what application I wanted to launch, and the other informing me that it contained "software intended to be run automatically. Would you like to run it?" I found the second dialog rather interesting since the application it detected was a Windows executable. This particular USB drive still contains LaunchU3.exe. I've changed the Windows registry on my machines to essentially block this feature and thus ignore it. I find it interesting that OpenSolaris still detects the "fingerprints" of the automatic execution capability of this thumb drive. At least OpenSolaris asked before blindly executing.
I'm beginning to think that perhaps this release of OpenSolaris is worth further investigation. But I've still got way to much life in front of me to waste time or money on installing this. Although perhaps installing a removable drive bay on europa would be a good investment. Hard drives are dirt cheap, and removable media for experimental purposes would be better than trying to create a multi-boot system.