Java (J2SE 1.5) Annotations

Just been reading about the addition of annotations to Java in its latest J2SE 1.5 incarnation.
It's good to see Sun is prepared to borrow from .NET, returning the complement so to speak.
Attributes (the .NET equivalent) is one of the two things I really like about .NET. The other
is assemblies, which sadly have no equivalent in the new Java release.

There are two really cool things about assemblies that you just don't get with Java's jars:

1. Assemblies support secure linking, you can't link against the wrong version of a dependency. For some interesting research on adding secure linking to Java, see http://www.cs.princeton.edu/sip/projects/modularity/.
   
2. Assemblies support reflection. In Java, you can only reflect upon low-level classes and methods. However, just came across http://jpf.sourceforge.net, which might help get the ball rolling.