So, I thought I would try the IDEA 13 EAP and ran into a couple of problems.
EAP build 132.556
Plugin version 23.250 from Cardea build page
First of all, it wouldn't run with a 1.6 JVM. Changed to a 1.7 JVM and
everything was fine.
Now it comes up, but none of the Scala files have any syntax coloring.
I tried "invalidate caches and restart", didn't help.
It's probably some simple new setting somewhere, but if someone could
suggest something, I would be quite appreciative.