Added Python 3.0 warning to cPickle.
diff --git a/Modules/cPickle.c b/Modules/cPickle.c
index 1dd35be..06726ee 100644
--- a/Modules/cPickle.c
+++ b/Modules/cPickle.c
@@ -5710,6 +5710,12 @@
 	PyObject *format_version;
 	PyObject *compatible_formats;
 
+	/* XXX: Should mention that the pickle module will include the C
+	   XXX: optimized implementation automatically. */
+	if (PyErr_WarnPy3k("the cPickle module has been removed in "
+			   "Python 3.0", 2) < 0)
+		return;
+
 	Py_TYPE(&Picklertype) = &PyType_Type;
 	Py_TYPE(&Unpicklertype) = &PyType_Type;
 	Py_TYPE(&PdataType) = &PyType_Type;