Mark dart:mirrors as having a (slightly) unstable API in the documentation.

sdk/lib/mirrors/mirrors.dart

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // For the purposes of the mirrors library, we adopt a naming
 // convention with respect to getters and setters.  Specifically, for
 // some variable or field...
 //
 //   var myField;
 //
 // ...the getter is named 'myField' and the setter is named
@@ skipping 26 matching lines @@
  * cases is [:o'.x(a'):] where *o'* and *a'* are Dart variables
  * bound to *o* and *a* respectively. Furthermore, *o'* and *a'*
  * are assumed to be fresh variables (meaning that they are
  * distinct from any other variables in the program).
  *
  * Sometimes the documentation refers to *serializable* objects.
  * An object is serializable across isolates if and only if it is an instance of
  * num, bool, String, a list of objects that are serializable
  * across isolates, or a map with keys and values that are all serializable across
  * isolates.
+ *
+ * ## Status: Unstable
+ *
+ * The dart:mirrors library is considered unstable and its API might
+ * change slightly as a result of feedback from users. There are two
+ * implementations of the library -- one for the native Dart VM and one
+ * for dart2js -- and they are both under development and may not
+ * support all operations yet.

[bakster, 2013/11/08 10:32:33]

- Remove "considered".
- use "user feedback".
- This library is platform dependent and it therefore has implementations for
both dart2js and the Dart VM. 
 
"not support all operations yet"  does not  match the lack of user feedback.
You might want to restate the last part.

  */
 library dart.mirrors;
 
 import 'dart:async';
 import 'dart:isolate';
 
 /**
  * A [MirrorSystem] is the main interface used to reflect on a set of
  * associated libraries.
  *
@@ skipping 503 matching lines @@
    * This map includes all regular methods, getters, setters, fields, classes
    * and typedefs actually declared in the library. The map is keyed by the
    * simple names of the declarations.
    */
   Map<Symbol, DeclarationMirror> get declarations;
 
   /**
    * Returns a map of the top-level methods, getters and setters of the library.
    *
    * The intent is to capture those members that constitute the API of a
-   * library. Hence fields are not included, but the getters and setters 
+   * library. Hence fields are not included, but the getters and setters
    * implicitly introduced by fields are included. Synthetic getters for the
    * types exported by the library are also included.
    *
    * The map is keyed by the simple names of the members.
    */
   Map<Symbol, MethodMirror> get topLevelMembers;
 
   /**
    * Returns [:true:] if this mirror is equal to [other].
    * Otherwise returns [:false:].
@@ skipping 600 matching lines @@
    *
    * When used as metadata on an import of "dart:mirrors", this metadata does
    * not apply to the library in which the annotation is used, but instead
    * applies to the other libraries (all libraries if "*" is used).
    */
   final override;
 
   const MirrorsUsed(
       {this.symbols, this.targets, this.metaTargets, this.override});
 }