Opensolaris reviewed at a Linux community board
A nice conclusion, especially when you consider that this review was published on a website called linux-hardcore.com:
OpenSolaris 2008.11 gave me a good impression. It's a system that works, even there are some compatibility issues which, according to the designers and developers, is in progressive solution. It's clean, neat, nice, well done, but without some software that is commonly used by most users. It's an operating system with a very promising future and may be not only able to replace the commercial operating systems, but also to compete with Linux and BSD. We need only give time to time. Congratulations to the developers!