I've written a lot of Scala, and really like the language (well, aside from them not ditching null and exceptions entirely), but years ago I stopped recommending it for new projects, especially in a corporate setting. It's hard to hire experienced Scala developers, and most Java developers I've worked with were either completely uninterested in writing Scala at all, or didn't care to learn the language well enough to actually make use of its better features, and somehow ended up writing Scala that looked like worse Java than the Java they'd usually write.
