A few small changes:
* The only exception we should catch when trying to import cStringIO is an
  ImportError.
* Delete the function signatures embedded in the mk*temp docstrings.
* The tempdir global variable was initialized twice.
diff --git a/Lib/tempfile.py b/Lib/tempfile.py
index e75c8fe..84ec6e0 100644
--- a/Lib/tempfile.py
+++ b/Lib/tempfile.py
@@ -39,7 +39,7 @@
 
 try:
     from cStringIO import StringIO as _StringIO
-except:
+except ImportError:
     from StringIO import StringIO as _StringIO
 
 try:
@@ -82,8 +82,6 @@
 
 template = "tmp"
 
-tempdir = None
-
 # Internal routines.
 
 _once_lock = _allocate_lock()
@@ -259,7 +257,7 @@
 tempdir = None
 
 def gettempdir():
-    """Accessor for tempdir.tempdir."""
+    """Accessor for tempfile.tempdir."""
     global tempdir
     if tempdir is None:
         _once_lock.acquire()
@@ -271,8 +269,7 @@
     return tempdir
 
 def mkstemp(suffix="", prefix=template, dir=None, text=False):
-    """mkstemp([suffix, [prefix, [dir, [text]]]])
-    User-callable function to create and return a unique temporary
+    """User-callable function to create and return a unique temporary
     file.  The return value is a pair (fd, name) where fd is the
     file descriptor returned by os.open, and name is the filename.
 
@@ -309,8 +306,7 @@
 
 
 def mkdtemp(suffix="", prefix=template, dir=None):
-    """mkdtemp([suffix, [prefix, [dir]]])
-    User-callable function to create and return a unique temporary
+    """User-callable function to create and return a unique temporary
     directory.  The return value is the pathname of the directory.
 
     Arguments are as for mkstemp, except that the 'text' argument is
@@ -341,8 +337,7 @@
     raise IOError, (_errno.EEXIST, "No usable temporary directory name found")
 
 def mktemp(suffix="", prefix=template, dir=None):
-    """mktemp([suffix, [prefix, [dir]]])
-    User-callable function to return a unique temporary file name.  The
+    """User-callable function to return a unique temporary file name.  The
     file is not created.
 
     Arguments are as for mkstemp, except that the 'text' argument is