On OS X 10.9.1
This works:

Python 2.7.5 (default, Aug 25 2013, 00:04:04) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __future__
>>> dir(__future__)
['CO_FUTURE_ABSOLUTE_IMPORT', 'CO_FUTURE_DIVISION', 'CO_FUTURE_PRINT_FUNCTION', 'CO_FUTURE_UNICODE_LITERALS', 'CO_FUTURE_WITH_STATEMENT', 'CO_GENERATOR_ALLOWED', 'CO_NESTED', '_Feature', '__all__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', 'absolute_import', 'all_feature_names', 'division', 'generators', 'nested_scopes', 'print_function', 'unicode_literals', 'with_statement']

This also works:

Python 3.1 (r31:73578, Jun 27 2009, 21:49:46) 
[GCC 4.0.1 (Apple Inc. build 5493)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __future__
>>> dir(__future__)
['CO_FUTURE_ABSOLUTE_IMPORT', 'CO_FUTURE_BARRY_AS_BDFL', 'CO_FUTURE_DIVISION', 'CO_FUTURE_PRINT_FUNCTION', 'CO_FUTURE_UNICODE_LITERALS', 'CO_FUTURE_WITH_STATEMENT', 'CO_GENERATOR_ALLOWED', 'CO_NESTED', '_Feature', '__all__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', 'absolute_import', 'all_feature_names', 'barry_as_FLUFL', 'division', 'generators', 'nested_scopes', 'print_function', 'unicode_literals', 'with_statement']


In Python 3.2 and 3.3 it appears broken.

Python 3.2.2 (v3.2.2:137e45f15c0b, Sep  3 2011, 17:28:59) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __future__
>>> dir(__future__)
Segmentation fault: 11

also

Python 3.3.0 (v3.3.0:bd8afb90ebf2, Sep 29 2012, 01:25:11) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import __future__
>>> dir(__future__)
Segmentation fault: 11

> Python 2.7.5 (default, Aug 25 2013, 00:04:04) 

You should try the version 2.7.6 which contains a fix for OS X 10.9:
http://www.python.org/download/releases/2.7.6/

This is a duplicate of Issue18458. The crash is caused by an incompatible change introduced in OS X 10.9 to the Apple-supplied version of libedit's readline compatibility layer and can affect Python versions that dynamically link with the system libedit (not all do).  Fixes for the problem were released with Python 2.7.6 and 3.3.3, and found in the latest binary installers for OS X on python.org. Bug fixes for Python 3.2.x are no longer being produced, only security fixes.  However, it *might* be possible to workaround the issue for 3.2 by installing the third-party deadline package from PyPI (https://pypi.python.org/pypi/readline).