Yes, having used IntelliJ for the past 5 years now, I was pleased to see IntelliJ 6.0 released, although since I am not on Java 5 project - I can't test many of its juicier features. Nonetheless, it appears the best version ever.
And if you are getting some performance issues for IntelliJ on Windows when
go to Settings -> General -> toggle Synchronize files on frame activation;
- set JDK (for running IntelliJ) to version 6 Mustang; by setting IDEA_HOME and overriding 'idea.no.jdk.check=true' in the idea.properties file