First off I'd like to say that I like the Indexing in the background.
However, there seems to be a few issues with the current build
Why is IDETalk disabled when indexing is active? Surely they should be independent of each other.
I have a project with 4 modules in it, 3 of them had the Project SDK listed (1.5), the 4th had 1.5 explicitly set instead of the Project SDK (even though they are identical). After setting the 4th to Project SDK, IDEA found it necessary to re-index the JDK!
If I add a jar to my project, IDEA indexes the JDK!