#3472: update Mac-bundled Python version info.

Doc/using/mac.rst

@@ -25,10 +25,10 @@ installers for the latest 2.3 release for Mac OS 9 and related documentation.
 Getting and Installing MacPython
 ================================
 
-Mac OS X 10.4 comes with Python 2.3 pre-installed by Apple. However, you are
-encouraged to install the most recent version of Python from the Python website
-(http://www.python.org). A "universal binary" build of Python 2.5, which runs
-natively on the Mac's new Intel and legacy PPC CPU's, is available there.
+Mac OS X 10.5 comes with Python 2.5.1 pre-installed by Apple.  If you wish, you
+are invited to install the most recent version of Python from the Python website
+(http://www.python.org).  A current "universal binary" build of Python, which
+runs natively on the Mac's new Intel and legacy PPC CPU's, is available there.
 
 What you get after installing is a number of things:
 
@@ -46,7 +46,10 @@ What you get after installing is a number of things:
 The Apple-provided build of Python is installed in
 :file:`/System/Library/Frameworks/Python.framework` and :file:`/usr/bin/python`,
 respectively. You should never modify or delete these, as they are
-Apple-controlled and are used by Apple- or third-party software.
+Apple-controlled and are used by Apple- or third-party software.  Remember that
+if you choose to install a newer Python version from python.org, you will have
+two different but functional Python installations on your computer, so it will
+be important that your paths and usages are consistent with what you want to do.
 
 IDLE includes a help menu that allows you to access Python documentation. If you
 are completely new to Python you should start reading the tutorial introduction