Language support for collections
Literal expressions for immutable lists, sets, and maps, and indexing-access syntax for lists and maps
Lambda expressions (informally, "closures") and defender methods for the Java programming language
The two features that I was looking forward to and IMO would actually make Java
somewhat tolerable less awful have been deferred to JDK 8 or later.
What little interest I had in Java 7 is now gone.