* nix-env now maintains meta info (from the `meta' derivation

attribute) about installed packages in user environments.  Thus, an
  operation like `nix-env -q --description' shows useful information
  not only on available packages but also on installed packages.

* nix-env now passes the entire manifest as an argument to the Nix
  expression of the user environment builder (not just a list of
  paths), so that in particular the user environment builder has
  access to the meta attributes.
  
* New operation `--set-flag' in nix-env to change meta info of
  installed packages.  This will be useful to pass per-package
  policies to the user environment builder (e.g., how to resolve
  collision or whether to disable a package (NIX-80)) or upgrade
  policies in nix-env (e.g., that a package should be "masked", that
  is, left untouched by upgrade actions).  Example:

  $ nix-env --set-flag enabled false ghc-6.4

doc/manual/release-notes.xml

@@ -14,6 +14,14 @@
 
   <listitem><para>TODO: multi-user support.</para></listitem>
 
+
+  <listitem><para><command>nix-prefetch-url</command> now by default
+  computes the SHA-256 hash of the file instead of the MD5 hash.  In
+  calls to <function>fetchurl</function> you should pass an
+  <literal>sha256</literal> attribute instead of
+  <literal>md5</literal>.  You can pass either a hexadecimal or a
+  base-32 encoding of the hash.</para></listitem>
+
   
   <listitem><para><command>nix-store</command> has a new operation
   <option>--read-log</option> (<option>-l</option>)
@@ -51,6 +59,14 @@
   
 
   <listitem><para>TODO: <option>--argstr</option>.</para></listitem>
+
+
+  <listitem><para>TODO: <command>nix-env</command> now maintains meta
+  info about installed packages in user
+  environments.</para></listitem>
+
+  <listitem><para>TODO: <command>nix-env</command>
+  <option>--set-flag</option>.</para></listitem>
   
 
   <listitem><para>TODO: new built-ins