Now that I've done a few trivial things with Scala (which I love for "hello world" and contrived applications!) I am left wondering.. part about maturity of the tools to support development, and part about general applicability. Are the toolsets ready? Is Scala appropriate for use on enterprise / business applications? Would "you" use it on a non-trivial project?

Some of my (possibly unfounded) concerns would be:

• are the IDE and toolsets as rich as what we have to develop .net and java applications (eclipse for Scala seems limited compared to eclipse for java)?
• are the build / CI / testing toolsets able to effectively deal with Scala?
• how maintainable is the concise code that can be (encouraged?) written in the language?
• is it possible to find developers with Scala experience?
• is there enough critical mass to get help through on-line reference and books that are more than "intro" to the language?

So bottom line - is the ecosystem mature enough to use now, or better off waiting to see how it evolves?

EDIT: let's say "non-trivial" is a multi-year, multi-release, 10-20 developers project.