One year ago Daniel Korzekwa posted on "Moving from Java to Scala" . Now, one year later, he follows up with "Moving from Java to Scala - One year later...".  This blog article gives a thoughtful evaluation of his years experience with Scala covering many practical aspects such as the Programming language, Testing, Performance, Tools, Language extensions, Interoperability, Monitoring and maintenance, Support, Scala skills and Time-to-Market.
If you are considering using Scala or have been asked to evaluate it then you may find the article an interesting and stimulating read.
After writing 8622 lines of code in Scala, Daniel stands back and assesses whether moving from Java to Scala was a good decision or simply a mistake.
It should be noted that Scala's future enhancement is assured for at least another 5 years both from EPFL funding and an ERC grant . There is also a growing set of commercial companies supporting Scala and a company, Scala Solutions , dedicated to providing Scala support products and Scala development tools.