There is one test failure with Python 3.0rc3 built on MacOS X 10.4.11 
(Intel).  Test  test_cmd_line fails in the very last test as follows:

% python.exe Lib/test/test_cmd_line.py
test_directories (__main__.CmdLineTest) ... ok
test_optimize (__main__.CmdLineTest) ... ok
test_q (__main__.CmdLineTest) ... ok
test_run_code (__main__.CmdLineTest) ... FAIL
test_run_module (__main__.CmdLineTest) ... ok
test_run_module_bug1764407 (__main__.CmdLineTest) ... ok
test_site_flag (__main__.CmdLineTest) ... ok
test_usage (__main__.CmdLineTest) ... ok
test_verbose (__main__.CmdLineTest) ... ok
test_version (__main__.CmdLineTest) ... ok

======================================================================
FAIL: test_run_code (__main__.CmdLineTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Lib/test/test_cmd_line.py", line 143, in test_run_code
    0)
AssertionError: 1 != 0

----------------------------------------------------------------------
Ran 10 tests in 2.074s

FAILED (failures=1)
Traceback (most recent call last):
  File "Lib/test/test_cmd_line.py", line 151, in <module>
    test_main()
  File "Lib/test/test_cmd_line.py", line 147, in test_main
    test.support.run_unittest(CmdLineTest)
  File ".../Python-3.0rc3/Lib/test/support.py", line 698, in 
run_unittest
    _run_suite(suite)
  File ".../Python-3.0rc3/Lib/test/support.py", line 681, in _run_suite
    raise TestFailed(err)
test.support.TestFailed: Traceback (most recent call last):
  File "Lib/test/test_cmd_line.py", line 143, in test_run_code
    0)
AssertionError: 1 != 0


The results for this code snippet:

        # Test handling of non-ascii data
        if sys.getfilesystemencoding() != 'ascii':
            command = "assert(ord('\xe9') == 0xe9)"
            self.assertEqual(
                self.exit_code('-c', command),
                0)

are:

% python.exe 
Python 3.0rc3 (r30rc3:67312, Nov 21 2008, 14:20:38) 
[GCC 4.0.1 (Apple Computer, Inc. build 5367)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.getfilesystemencoding()
'utf-8'
>>> ord('\xe9') == 0xe9
True