J2SE 5.0 featues

Generics
Enhanced for Loop
Autoboxing/Unboxing
Typesafe Enums
Varargs
Static Import
Metadata (Annotations)
Instrumentation
Enumerations
Enhanced for each loop
Static imports
Automatic stub generation for RMI objects.
The concurrency utilities in package java.util.concurrent.
Scanner class for parsing data from various input streams and buffers