Earlier this year, we asked our readers why people thinking of Linux aren't also thinking of OpenSolaris (or vice versa), now that both are pukka OSS operating systems.
Well, one reason that people might choose to miss out on OpenSolaris is because we're (in general) a conservative lot – once bitten, twice shy – and a lot of people have had bad experiences with Solaris (and, dare we say it, also with Windows and Linux) in the past. No matter how much software and UI improves, it takes ages for the community to accept this. A reputation that took years to build can be lost with one bad release – but won't be quickly reinstated with one good one. So there will always be people who resist change – and why not, if what they have now works for them.
However, various people pointed us at Ubuntu and "an OpenSolaris-based distro focused specifically on developers". So perhaps things have improved for Solaris lately and, as I said in the original article, it's now worth another look.