The following compiles with javac 8 b121:

static void m(Object dummy, int arg) { System.out.println("int"); }
static void m(Object dummy, Integer arg) { System.out.println("Integer"); }

public static void main(String... args) {
  m(0, 23);
  m(0, Integer.valueOf(23));
}

(The first invocation prints "int"; the second prints "Integer".)

This was an experimental feature in Lambda that we ultimately agreed to undo for 8.  The return expressions of _lambdas_ should continue to get special treatment, but a top-level argument should not.  The only mechanism for treating one parameter type as better than another in this case should be subtyping.