I just tried the daily dev build (NetBeans 6.1 Dev 200802080008) for OS X. It is almost there for my daily work – my current Java development project (a commercial version of my old NLBean open source project with a new AI NLP module), Scala coding experiments, and new Rails projects all work great. The one problem: I get errors when using existing Rails NetBeans projects (actually, I get the same errors when trying to modify project properties in new Rails projects but new projects can be created with the desired properties). Close, but not quite there. BTW, the Scala NetBeans plugins, which are very new, are looking very good.