I just started working with Nika, setting up a simple project with 3rd party JAR dependencies.
I was dismayed to learn that the ability to specify library or source JARs by selecting all in a single /lib directory was missing. I think that was one of the best changes in IntelliJ 9/10. The new UI has more of a Maven flavor, which I personally don't care for.
If the Maven tie must be stronger, so be it. But I'd like to see the IntelliJ 10 library specification methods remain.