Another one you may be missing is
Juniper Networks.
While I can't just list the set of clients that typesafe has, I will say that Scala *is* seeing increased adoption in larger corporations. At this point, it's still the kind of thing that's hush hush, and not public. SO the ones most people know about are the ones that were non-public a while ago, and are now announcing.
Having been in the scala community since 2006/7-ish, I'll say that we're seeing a *lot* of companies taking serious looks at scala. In particular, Akka has been a prominent driver of adoptions for folks who already have large JVM systems and are looking add new services.
In any case, from what I can see in my neck of the woods, Scala adoption is on the rise. More conservative organizations are in the evaluate/prototype stage right now. Once a few them are successful, I think we'll see how many more announce public Scala usage/projects.
That's my $.02, would love to hear others.