Other than that I work for Sun and that I believe in the "fly your own plane / eat your own dog food" principle, I've never had a reason to seriously consider using OpenSolaris. Why? Because I'm a very happy Ubuntu user, especially since the latest release, Intrepid Ibex, version 8.10, as I described about a month ago in Ubuntu 8.10 (Intrepid Ibex): Very Impressive!
However, two days ago I attended an OpenSolaris Install Fest, organized by Roman Strobl and other OpenSolaris guys in Prague, admittedly with a degree of scepticism (and more than anything else for the consumables promised after the session). There was a lot of talk about what OpenSolaris is and so on, etc. Roman did a very visual demo (watch it on-line here), basically going through the main features of OpenSolaris, focusing on the improvements in the latest release. (I particularly liked it when he revealed that one can now use the "sudo" command in OpenSolaris too!)
But, for me (and others I talked to after the presentations were over) the absolute killer feature is the "Time Slider". Roman showed it in a split second but could have spent several minutes on it, in my humble opinion. I pretty much immediately set up VirtualBox (for the first time... and it was pretty intuitive) and then installed OpenSolaris through VirtualBox (also intuitive). By the time I had set up the JDK and NetBeans, I had several installers on my desktop:
I created a new folder and put them all into that, as you can see when I move the slider further along the scale:
Not bad, right? Stuff I deleted reappeared when I moved the slider into the past. Time travel... now possible with OpenSolaris. And in a really cool and fun way too. I might have to move out of VirtualBox, abandon Ubuntu altogether, and switch to OpenSolaris. Especially now that all my drivers seem to be supported.