More Scala - is it worth migrating from Java?

After recently playing with Scala, I discovered somebody who did so more methodically and tried it out for a year. He breaks down using Scala to a number of categories and rates them from 1-5. His conclusion:

To summarise Scala evaluation, this is a scores matrix for all categories (1 - poor, 2 - fair, 3 - good, 4 - very good, 5 - excellent).

• Programming language - very good (4)
• Testing - very good (4)
• Performance - very good (4)
• Tools - fair (2)
• Language extensions - good (3)
• Interoperability - excellent (5)
• Monitoring and maintenance  - good (3)
• Support - good (3)
• Scala skills - poor (1)

A good read, especially if your curiosity was at all piqued by Scala from my entry last week. I very much agree that, while pushing Scala for "enterprise" is a bit risky (though at least moderately feasible due to the interoperability), it is definitely a worthy tool for personal use.