I hope they're going to fix the Scala and Play plugins. Unfortunately they say nothing about it. Sometimes the lag between typing and actually seeing it in Idea is a couple of seconds.. Still better than the last time I tried Scala IDE (eclipse) though.
Also, I find the code style settings to be extremely difficult to tweak, in large part due to poor browsability and also because you can't actually see them applied to the example code next to the settings editor.